macOS Big Sur
macOS Big Sur (version 11) is the seventeenth major release of Apple's macOS operating system, succeeding macOS Catalina and introducing a redesigned interface inspired by iOS and iPadOS.[1] Named after the scenic Big Sur coastal region in central California, it continues Apple's tradition of naming macOS versions after California landmarks.[2] Announced at the 2020 Worldwide Developers Conference on June 22, 2020, macOS Big Sur was released to the public on November 12, 2020, as a free software update for compatible Mac models.[1][3] The operating system emphasizes a modern, spacious design that enhances navigation and focus, with translucent interface elements, rounded corners, and a refined Dock.[1] Key updates include a faster, more privacy-focused Safari browser with Intelligent Tracking Prevention; enhanced Messages app supporting pinned conversations, effects, and easier photo sharing; and an improved Maps application with 3D indoor views, cycling directions, and guides.[3] Additional features encompass better Control Center and Notification Center customization, and strengthened privacy tools like Safari's Privacy Report for blocked trackers.[1] macOS Big Sur is compatible with a broad range of Intel-based Macs, including MacBook models from 2015 onward, MacBook Air from 2013, MacBook Pro from late 2013, iMac from 2014, iMac Pro from 2017, Mac Pro from 2013, and Mac mini from late 2014, as well as all Apple silicon Macs.[4] It requires at least 4 GB of RAM and 35.5 GB of available storage for installation, marking a shift toward supporting both Intel and Apple silicon architectures in subsequent updates.[4] The final version, 11.7.10, was released on September 11, 2023, providing ongoing security patches until support ended.[5]Development
Announcement and previews
Apple announced macOS Big Sur on June 22, 2020, during the keynote presentation at its Worldwide Developers Conference (WWDC) 2020.[1] The operating system, internally versioned as macOS 11, marked a significant shift from the long-standing 10.x numbering scheme that had defined the platform since its inception in 2001. The name "Big Sur" draws inspiration from the scenic coastal region along California's central coast, upholding Apple's tradition of naming macOS releases after notable landmarks and natural features within the state, such as Yosemite and Mojave in prior versions.[1] This choice evoked the area's dramatic landscapes, aligning with the update's emphasis on a refreshed, visually striking interface. Key previews during the WWDC keynote highlighted the adoption of an iOS-inspired design language, featuring rounded corners, translucent elements, and a more unified aesthetic across Apple's ecosystem.[1] The presentation also introduced the first public details of Apple's transition to its custom Apple silicon chips, signaling a move away from Intel processors to enhance performance and integration with iOS apps. Early demonstrations included video segments and on-screen screenshots showcasing the redesigned Dock, menu bar, and full-screen app windows with frosted glass effects for improved depth and readability.[1] Attendees saw previews of interactive widgets in the Notification Center, allowing customizable glances at information like weather and calendars, alongside seamless app integrations such as enhanced Messages with effects and group pinning, and an updated Maps app with 3D globe views.[1] These visuals underscored Big Sur's promise of bridging macOS and iOS experiences while introducing novel capabilities like a customizable Control Center.Beta program and testing
Following the announcement at WWDC 2020, Apple released the first developer beta of macOS Big Sur (version 11.0 build 20A4299v) on June 22, 2020, to registered members of the Apple Developer Program via the developer portal.[1] This initial build allowed developers to test core features, including the redesigned interface and support for upcoming Apple silicon architecture, with subsequent betas issued regularly through September 2020 to address bugs and refine functionality.[6] For instance, betas 2 through 6, released between July and August 2020, focused on fixing issues like Wi-Fi connectivity and app crashes reported in early testing.[7] The public beta program opened to broader testing on August 6, 2020, for users enrolled in the Apple Beta Software Program, providing access to the then-current beta build and later iterations through the beta.apple.com portal.[8] Although initially previewed for a July rollout, the public beta was delayed to allow additional developer validation, enabling non-developers to contribute feedback on everyday usage scenarios.[1] By September 2020, public betas aligned closely with developer versions, incorporating iterative updates for enhanced reliability.[9] Testing efforts prioritized stability across Intel-based Macs and early Apple silicon prototypes, such as the Developer Transition Kit hardware provided to select developers, to ensure seamless performance during the transition to ARM architecture.[7] Key focus areas included compatibility with third-party applications, where issues like Rosetta 2 emulation for Intel apps on Apple silicon were refined, and overall system performance optimizations to reduce latency in UI elements and multitasking.[10] Beta participants reported and resolved challenges with driver support and file system integrity, contributing to broader ecosystem readiness.[8] Feedback from both developer and public testers drove key milestones, including UI refinements such as reduced menu transparency for better readability and improved contrast in window elements, implemented across betas 8 through 10 to address visual consistency complaints.[11] These changes, informed by thousands of reports submitted via Apple's Feedback Assistant tool, helped stabilize features like the new Control Center and Notification Center before the candidate releases in October 2020.System requirements
Hardware compatibility
macOS Big Sur requires a 64-bit processor (Intel or Apple silicon), at least 4 GB of RAM, and a minimum of 35.5 GB of available storage space for installation when upgrading from macOS Sierra or later (up to 44.5 GB from earlier versions).[4] Some features, such as iCloud and the App Store, necessitate an Apple ID.[4] The operating system supports the following Mac models, all equipped with compatible Intel processors at release, with later models incorporating Apple silicon: MacBook from 2015 or later; MacBook Air from 2013 or later; MacBook Pro from Late 2013 or later; iMac from 2014 or later; iMac Pro from 2017 or later; Mac Pro from 2013 or later; and Mac mini from 2014 or later.[4] This compatibility profile marked the end of official support for numerous legacy models, including MacBook and MacBook Pro units from 2008 to mid-2014, MacBook Air models from 2008 to early 2013, iMacs from 2009 to mid-2013, Mac minis from 2009 to late 2012, and Mac Pros from 2006 to mid-2012, among others prior to the specified cutoffs.[4] Users with these unsupported machines were unable to upgrade to Big Sur through standard methods, potentially leaving them on macOS Catalina or earlier versions that eventually ceased receiving security updates, thereby increasing vulnerability risks and limiting access to new software features.[12] macOS Big Sur introduced native support for Apple silicon, specifically the M1 chip debuted in select 2020 Mac models such as the MacBook Air, MacBook Pro, Mac mini, and iMac, enabling direct ARM-based execution without reliance on emulation for Intel apps during the transition period.[13] This shift optimized performance and power efficiency on these new hardware platforms while maintaining backward compatibility for x86-64 applications via Rosetta 2.[13]Installation prerequisites
To upgrade to macOS Big Sur, the source system must be running macOS Sierra 10.12 or later, requiring at least 35.5 GB of available storage space; upgrades from earlier versions of macOS demand up to 44.5 GB due to additional processes such as file system conversion.[4] For downloading the full installer via the App Store, the Mac must be on OS X 10.9 Mavericks or later, though practical upgrades typically start from more recent versions compatible with Software Update.[4] Clean installations necessitate creating a bootable USB installer from the downloaded package or using macOS Recovery mode, which supports reinstallation without an existing OS but requires an internet connection for downloading the installer.[14][15] An Apple ID is mandatory for downloading the macOS Big Sur installer from the App Store and enabling post-installation features such as iCloud synchronization and App Store access; terms and conditions apply to Apple ID usage.[4][16] Without an Apple ID, alternative methods like macOS Recovery over the internet can be used for reinstallation on compatible hardware, but full feature activation remains limited.[17] Apple strongly recommends creating a full backup using Time Machine before any upgrade or installation to safeguard against potential data loss, utilizing an external storage device formatted for Time Machine compatibility.[16][18] The backup process should include all user files, applications, and system settings to facilitate restoration if issues arise during the procedure. For supported systems, the primary upgrade path involves over-the-air updates through System Preferences > Software Update, which automatically checks compatibility and downloads the installer while preserving user data and converting the startup disk to APFS if it was previously on HFS+ or other legacy file systems.[16][14] On older macOS versions without Software Update availability for Big Sur, users must manually download the installer from the App Store and run it, triggering the same APFS conversion as needed to support Big Sur's requirements for optimized performance and encryption.[4][19]Design overhaul
Visual and aesthetic changes
macOS Big Sur marked the first comprehensive visual redesign of the operating system since macOS Yosemite in 2014, adopting elements from iOS 14 such as rounded corners, translucent materials, and a more vibrant color palette to foster a unified aesthetic across Apple's ecosystem. This approach aimed to modernize the interface while maintaining familiarity, reducing visual clutter and emphasizing content through a cleaner, more spacious layout.[1][20] The iconography received a thorough overhaul, with system apps and folders featuring updated flat designs that incorporate colorful accents, subtle depth via shadows, and a standardized rounded square shape for consistency. For example, icons like those for Messages and Calendar were refreshed to align more closely with their iOS versions, using front-facing perspectives and uniform drop shadows to add dimension without overwhelming the minimalist style. This redesign extended to the Dock, where icons were thoughtfully updated to harmonize with broader Apple platform visuals while preserving the Mac's distinct personality.[1][21][20] Windows and menus underwent subtle yet impactful refinements, including softer, more rounded edges on window corners, brighter title bars with reduced contrast, and enhanced translucency in materials to create a sense of depth and layering. Menu bars became taller and more adaptive, shifting translucency levels and text colors based on light or dark mode preferences for seamless theme consistency, while sidebar layouts in native apps were improved for better spatial organization and visual flow. These changes collectively contribute to a more immersive and cohesive desktop environment.[1][20] Typography in macOS Big Sur builds on the San Francisco system font, incorporating refinements such as variable weights and optical sizing adjustments for enhanced legibility across different scales and contexts. Paired with these are smoother animations and transitions, including spring-like emergence for dialog boxes, which lend a fluid, responsive feel to interactions and reinforce the overall modern aesthetic.[22][20]User interface components
macOS Big Sur introduced the Control Center, a modular panel accessible from the menu bar that provides quick toggles for essential settings including Wi-Fi, Bluetooth, display brightness, and Do Not Disturb.[1] This panel consolidates previously scattered controls into a single, iOS-inspired interface, allowing users to adjust volume, screen mirroring, and AirDrop without navigating menus.[23] Customization is available through System Preferences > Dock & Menu Bar, where users can add, remove, or rearrange modules such as battery status, VPN connections, or accessibility shortcuts, and even drag individual controls to the menu bar for persistent access.[23] The Notification Center in macOS Big Sur received significant enhancements, presenting a unified view that combines notifications with interactive widgets for at-a-glance information.[1] Widgets, now redesigned in small, medium, and large sizes, include options for weather forecasts, calendar events, and news updates, enabling users to interact directly within the center for tasks like replying to messages or marking events.[1] Notifications themselves became more interactive, supporting quick replies and actions without opening full apps, improving workflow efficiency while maintaining a single-column layout for clarity.[1] Updates to the Dock and menu bar in macOS Big Sur emphasized consistency and usability, with the Dock featuring larger, refined icons designed to align with Apple's ecosystem-wide aesthetics while preserving macOS's distinct personality.[1] Users can enable auto-hiding for the Dock via System Preferences > Dock & Menu Bar to maximize screen space, with the bar sliding in and out on hover or gesture.[24] The menu bar integrates seamlessly with Siri, featuring a prominent Siri icon for voice-activated suggestions and commands, alongside the new Control Center icon positioned just to its left for streamlined access to system controls.[3] Finder in macOS Big Sur incorporated tabbed browsing improvements, allowing users to open and manage multiple folders within a single window using redesigned tabs that support drag-and-drop to create new tabs and contextual menus for better navigation.[25] Column view saw enhancements with refined layouts and integrated previews, enabling smoother file hierarchy traversal and quick metadata inspection without switching views.[26] Gallery mode for files was optimized for visual browsing, displaying large thumbnails with overlaid details like file size and creation date, facilitating easier identification and selection of media and documents.[26] These changes, combined with full-height sidebars, made file management more intuitive and aligned with iPadOS conventions.[1]Core system enhancements
Hardware and architecture support
macOS Big Sur marked a pivotal shift in Apple's hardware architecture strategy, introducing native support for the company's new Apple silicon processors based on ARM architecture, starting with the M1 chip. This transition began with Big Sur's release on November 12, 2020, coinciding with the launch of the first Apple silicon-equipped Macs, including the MacBook Air, 13-inch MacBook Pro, and Mac mini. The operating system was designed to run natively on these ARM-based systems, leveraging the integrated performance and efficiency of the M1 SoC, which combines CPU, GPU, Neural Engine, and other components on a single die. To facilitate the architecture change, Big Sur incorporated Rosetta 2, a binary translation layer that enables x86-64 applications built for Intel processors to run seamlessly on Apple silicon without requiring developers to rewrite code. Rosetta 2 dynamically translates Intel instructions to ARM equivalents at runtime, providing near-native performance for most apps while maintaining compatibility for legacy software. This emulation technology builds on the original Rosetta from the PowerPC-to-Intel transition, but with significant optimizations for modern workloads. Additionally, Big Sur introduced Universal 2 binaries, an updated format allowing developers to compile a single app bundle that includes both Intel and Apple silicon executables, enabling automatic selection of the appropriate binary at launch for optimal performance across hardware. The adoption of Apple silicon in Big Sur yielded notable performance and efficiency gains on supported hardware. For instance, M1-based Macs running Big Sur demonstrated up to 3.5 times faster CPU performance and six times faster GPU performance compared to equivalent Intel models, alongside improved battery life—such as up to 20 hours of wireless web browsing on the 2020 MacBook Air. These enhancements stemmed from the M1's unified memory architecture and power-efficient design, which reduced latency and power consumption during intensive tasks like video editing or machine learning. Big Sur also briefly referenced support for iOS and iPadOS apps on Apple silicon Macs, allowing developers to opt-in for running mobile apps natively or via emulation. Despite the forward-looking Apple silicon focus, Big Sur maintained full backward compatibility with Intel-based Macs, supporting a wide range of models from 2013 onward, including iMacs, MacBooks, and Mac Pros. This dual-architecture approach ensured a smooth transition period, with Intel Macs receiving security updates and feature enhancements through subsequent Big Sur point releases until their eventual shift to later macOS versions. The strategy allowed Apple to phase in Apple silicon gradually while minimizing disruption for users reliant on existing hardware.Security and integrity features
macOS Big Sur introduced a signed system volume (SSV), a cryptographic technology that protects core operating system files from unauthorized modification or replacement by malicious software. This feature uses digital signatures from Apple to verify the integrity of system files, preventing their execution or access without a valid signature. The SSV employs a structure of cryptographic hashes, including a Merkle tree and a master "seal" hash, to ensure immutability; if the seal is broken due to tampering, the system cannot boot, requiring reinstallation to restore integrity. By separating the read-only System volume from the writable Data volume, the SSV raises protection against rootkits and other malware that target OS components, while enabling faster background software updates without full restarts.[27][28] FileVault in macOS Big Sur provides full-disk encryption for the Data volume using XTS-AES-256, securing user files and applications while the sealed System volume handles OS integrity separately. Enhancements include improved recovery options, where users generate a personal recovery key tied to their Apple ID for data access if the login password is forgotten, reducing the risk of permanent data loss. On Macs with Apple Silicon or T2 chips, FileVault integrates with the Secure Enclave, a dedicated hardware component that stores encryption keys securely and performs encryption/decryption operations, enhancing overall performance and protection against key extraction attacks. This setup ensures seamless, hardware-accelerated encryption without impacting daily use.[29] Gatekeeper and XProtect received updates in macOS Big Sur to strengthen app security through stricter notarization and malware detection. Gatekeeper enforces mandatory notarization, requiring developers to submit apps to Apple for automated malware scanning and code verification before distribution; unnotarized apps trigger multiple warning dialogs, making unauthorized software harder to run. On Apple Silicon Macs, Gatekeeper further requires code signing, disallowing unsigned binaries entirely. XProtect complements this with real-time scanning, checking apps for known malware signatures upon download from the internet or launch, blocking threats proactively without user intervention. These layered defenses ensure only verified software executes, mitigating risks from malicious downloads.[30][31] Privacy features in macOS Big Sur emphasize user consent through granular app permission prompts, enhancing control over sensitive hardware and data access. Apps must request explicit permission for location services, displaying a system dialog where users can grant, deny, or limit access to precise or approximate location. Similarly, camera and microphone access triggers on-demand prompts, with permissions revocable via System Settings > Privacy & Security, preventing unauthorized surveillance or recording. These controls build on the Transparency, Consent, and Control (TCC) framework, logging access attempts and allowing one-time or persistent grants, thereby safeguarding personal information from rogue applications.[32][33]Backup and search improvements
macOS Big Sur introduced enhancements to Time Machine, enabling support for APFS-formatted backup disks for the first time, which improves backup speed and efficiency compared to previous HFS+ requirements.[34] This overhaul leverages APFS snapshots to create local backups directly on the startup disk, allowing users to restore previous file versions without needing an external drive attached.[35] Encrypted backups are also natively supported on APFS volumes, providing stronger protection for stored data during the backup process.[36] Spotlight received performance and usability upgrades in macOS Big Sur, including faster search results and the ability to preview content such as documents and images directly within the Spotlight window.[37] These changes facilitate quicker information retrieval, with added support for natural language queries through deeper integration with Siri, enabling more intuitive searches like "show me photos from last summer." Privacy-focused indexing ensures that sensitive data, such as passwords and certain system files, is excluded from searches to protect user information.[38] The software update system in macOS Big Sur was redesigned for a more streamlined experience, incorporating background downloads that allow updates to proceed without interrupting user activity.[39] Staged installations enable partial updates to be applied incrementally, reducing downtime, while delta updates deliver smaller patches by only downloading changes from previous versions, minimizing bandwidth usage for security fixes and minor releases.[16] Siri improvements in macOS Big Sur emphasize enhanced privacy and accessibility, with increased on-device processing on Apple Silicon Macs to handle common requests offline without sending data to servers.[38] This shift reduces latency and bolsters data protection by limiting cloud dependency, while the updated interface aligns with the system's new design for seamless interaction across apps and system functions. Signed system volumes further ensure backup integrity by verifying the authenticity of system files during recovery processes.[4]Application updates
Browser and communication apps
macOS Big Sur introduced Safari 14, which brought several enhancements to web browsing, including a redesigned interface with a customizable start page featuring background images, favorites, and privacy settings.[1] Users can now enable picture-in-picture mode for any video playing in the browser, allowing seamless viewing in a floating window while multitasking.[1] Privacy protections were strengthened through Intelligent Tracking Prevention, which blocks cross-site trackers more effectively and provides a new Privacy Report accessible from the address bar to visualize blocked trackers.[40] The Messages app in macOS Big Sur received significant updates to improve communication, enabling users to apply full-screen effects to iMessages for more expressive interactions.[3] Group chats gained pinning capabilities, allowing up to nine conversations to be fixed at the top of the list for quick access, along with features like mentions to notify specific participants.[3] Integration with iOS elements, such as Memoji stickers and custom text effects, was deepened, facilitating consistent messaging experiences across Apple devices.[1] Safari's built-in translation extension in macOS Big Sur allows users to translate entire webpages directly in the browser without third-party tools, supporting languages like English, Spanish, French, and more, with the option to download additional language models offline.[41] This feature detects the page's language automatically and provides a toggle in the Smart Search field for instant translation.[41] Underlying these updates, WebKit—the rendering engine powering Safari—saw improvements in macOS Big Sur, including support for WebP images for faster loading and HDR video playback for enhanced media quality.[40] JavaScript execution performance was optimized through engine refinements, resulting in quicker page rendering and better responsiveness for dynamic web content.[40] Security enhancements addressed multiple vulnerabilities, such as those in WebKit's handling of maliciously crafted content, to prevent potential exploits.[40]Productivity and media apps
The Notes app in macOS Big Sur received enhancements focused on organization and content creation, including the introduction of table support to allow users to insert, edit, and format tabular data directly within notes for structured information management. Folders for grouping notes were refined to support nested subfolders, improving hierarchical organization, while the app continued to provide seamless cross-platform synchronization with iOS devices through iCloud, ensuring notes and attachments remained accessible across Apple ecosystems. These updates built on the app's existing capabilities, emphasizing productivity for users handling lists, outlines, and collaborative content.[42] The Reminders app in macOS Big Sur introduced new functionality for task management, including the ability to assign reminders to other people in shared lists, with notifications sent to assignees. Smart suggestions based on past reminders help users quickly add recurring tasks, and support for tags enables better organization and searching across lists. These features enhance collaborative and personal productivity, with iCloud syncing for consistency across devices.[42] In the Photos app, library organization was bolstered by expanded facial recognition to include pets, integrating dogs and cats into the People album alongside human subjects for easier searching and grouping of personal media. This machine learning-driven feature analyzed photo libraries to suggest and confirm pet identities, enhancing album curation without manual tagging. Additionally, new effects for Live Photos—such as Long Exposure and a refined Loop mode—were added, enabling users to apply creative transformations to motion-captured images captured on compatible iPhones, with non-destructive editing preserved in the library. These changes prioritized intuitive media management and artistic expression in a redesigned interface aligned with Big Sur's aesthetic.[43][44] The Music app in macOS Big Sur added a Listen Now tab, centralizing access to recently played songs, personalized playlists, and Apple Music recommendations for streamlined music discovery and playback. Additional refinements improved navigation and integration with the system's media controls, supporting both local libraries and streaming services.[45] The Maps app underwent a comprehensive redesign in macOS Big Sur, introducing the Guides feature, which curates personalized recommendations for locations, activities, and itineraries from partners like Lonely Planet and Apple editors, with options to create and share custom guides. Look Around delivered immersive 360-degree street-level imagery in supported cities, allowing users to virtually explore areas before navigating. Routing improvements included dedicated options for cycling paths and electric vehicle charging stops along routes, with seamless handoff to iPhone for turn-by-turn directions; detailed indoor maps for major airports and malls further aided real-world navigation. These additions transformed Maps into a more exploratory tool, integrating with the system's updated visual style for fluid interaction.[1][46] Quick Look enhancements in macOS Big Sur improved file previews across documents and media, offering more interactive capabilities such as direct video trimming, audio playback controls, and image rotation within the viewer, reducing the need to launch full applications for quick assessments. Support for a broader range of file formats ensured sharper, more detailed thumbnails and previews in Finder, particularly for PDFs, images, and videos, streamlining workflow efficiency in the updated system environment. These refinements maintained Quick Look's role as a lightweight tool while aligning with Big Sur's emphasis on performant, glanceable interactions.[47]Store and utility apps
The Mac App Store in macOS Big Sur underwent a significant redesign aligned with the system's overall aesthetic overhaul, featuring a more modern layout with full-width app previews, enhanced visual elements like rounded corners, and streamlined navigation for easier browsing. This update included the introduction of privacy nutrition labels for apps, which transparently disclose data collection practices such as usage tracking, location access, and third-party information sharing to empower user-informed decisions. Additionally, a new dedicated category for Safari extensions was added, complete with editorial spotlights, top charts, and improved search functionality to simplify discovery and installation of browser add-ons.[1][3] Family Sharing capabilities were expanded in the App Store to encompass third-party in-app purchases and subscriptions, enabling up to six family members to share access without individual costs, thereby promoting collaborative use of premium content and services. Apple Arcade integration was further seamless, with a prominent Arcade tab in the sidebar providing one-tap access to over 100 ad-free, controller-supported games available via subscription, optimized for Mac playback including keyboard and trackpad controls. These enhancements collectively aimed to create a more unified and user-centric app distribution ecosystem.[1][48] The Voice Memos utility app received updates focused on usability and quality, including native iCloud syncing to automatically back up and access recordings across Apple devices like iPhone and iPad. Basic editing tools were refined, allowing users to trim clips, rename files, and organize recordings into folders directly within the app. A key addition was the Enhance Recording option, which applies real-time audio processing to minimize background noise and room reverberation, improving clarity for lectures, meetings, or creative ideas with minimal effort. While full automatic transcription arrived in subsequent macOS versions, Big Sur laid groundwork with improved audio handling for future expansions.[49] Developer tools saw substantial advancements with the release of Xcode 12 alongside macOS Big Sur, which defaults to building Universal apps capable of running natively on both Intel-based and Apple Silicon Macs without requiring code modifications. This support facilitated the transition to Apple silicon hardware announced in 2020, incorporating SwiftUI enhancements for creating consistent interfaces across macOS, iOS, and iPadOS. Developers also gained new APIs for Mac Catalyst apps to adopt the Big Sur design language and integrate features like Family Sharing for subscriptions. In a related development, macOS Big Sur enabled compatibility with iOS and iPadOS apps in the Mac App Store on Apple Silicon Macs, broadening the available software ecosystem.[50][51]Feature removals and deprecations
Discontinued user features
In macOS Big Sur, Apple continued the trend of streamlining the user interface by eliminating several legacy features that had become outdated or less secure, focusing on modern alternatives to enhance usability and security. The menu bar also saw refinements to legacy items, including the elimination of certain customizable options for the clock display and unused status indicators that cluttered the interface in prior versions. For instance, the ability to completely hide the clock from the menu bar—previously available in System Preferences > Date & Time—was removed, as the clock now serves as the entry point to Notification Center and cannot be disabled without third-party interventions. Analog clock styles persisted as an option to minimize visual footprint, but options for flashing the time or showing seconds were consolidated under Dock & Menu Bar preferences, reducing redundancy while prioritizing the new translucent design aesthetic. Unused status items, such as outdated battery or volume indicators from older hardware, were phased out to support the unified Control Center module.[52][53] Additionally, the Network Utility app, a diagnostic tool for network information and testing since Mac OS X 10.0, was deprecated and removed in macOS Big Sur. This app provided features like port scanning, ping, and lookup, but Apple directed users to Terminal commands or third-party alternatives for similar functionality, aligning with the shift toward command-line tools and integrated system diagnostics.[54] These changes impacted users by necessitating adaptation to more centralized tools, but Apple provided migration paths to minimize disruption. Menu bar simplifications encouraged reliance on the new Control Center for quick toggles, reducing cognitive load in the redesigned interface, though some power users expressed frustration over lost granular controls. For Network Utility users, documentation on equivalent Terminal commands was made available. Overall, these discontinuations supported Big Sur's goal of a cleaner, iOS-inspired experience without compromising core functionality.[1]Deprecated developer tools
macOS Big Sur fully discontinued support for 32-bit applications, building on the deprecation initiated in macOS Mojave and the complete removal in macOS Catalina, requiring developers to recompile all apps as 64-bit binaries for compatibility.[55][56] This shift ensured that applications could run natively on both Intel-based and the newly introduced Apple silicon architectures, eliminating legacy 32-bit code paths that limited performance and security. Developers were advised to use Xcode's architecture settings to build universal binaries supporting both x86_64 and arm64, with tools likelipo for merging binaries during the transition.[57]
The Carbon framework, a legacy C-based API for cross-platform compatibility, was removed in macOS Catalina following its deprecation in prior releases, and remains unsupported in Big Sur, with Apple strongly encouraging migration to the modern Cocoa and AppKit frameworks for user interface and system integration.[55] Specific Carbon components, such as Ink APIs and file manager routines, were marked obsolete as early as macOS Mojave, and by Big Sur, reliance on Carbon leads to compatibility failures, particularly on Apple silicon where 64-bit Cocoa APIs provide equivalent functionality with better performance.[58] This deprecation streamlined app development by unifying APIs under Objective-C and Swift paradigms, reducing maintenance overhead for cross-architecture support.
OpenGL, the cross-platform graphics API, remained deprecated in macOS Big Sur as announced in macOS Mojave, with no further development or feature additions, prompting developers to adopt the Metal graphics and compute API for hardware-accelerated rendering.[55] While OpenGL 4.1 implementations continued to function for backward compatibility on both Intel and Apple silicon Macs, apps using it faced potential performance issues and were ineligible for App Store updates without Metal migration. Metal offered superior integration with macOS's graphics stack, including support for unified memory architecture on Apple silicon, enabling more efficient GPU utilization.
To assist developers in updating apps for macOS Big Sur and Apple silicon, Apple provided comprehensive migration resources, including guides on creating universal binaries, handling architecture-specific code, and replacing deprecated APIs with modern alternatives like DriverKit for kernel extensions.[57] These resources emphasized testing with Xcode's Rosetta 2 emulation for Intel apps on arm64 hardware, alongside documentation for transitioning from legacy frameworks to ensure seamless performance across the hybrid Intel-Apple silicon ecosystem introduced in Big Sur.[59]
Reception and legacy
Critical reviews and user feedback
Upon its release, macOS Big Sur received generally positive reviews from critics, who praised its refreshed design language that brought macOS closer to the aesthetic of iOS and iPadOS, marking the most significant visual overhaul since the introduction of Aqua in Mac OS X. The Verge awarded it an 8.5 out of 10, highlighting the "neat new look" and overall stability of the final release, while noting that it achieves better familiarity for iPhone and iPad users without the disruptive changes seen in macOS Catalina.[60] Similarly, CNET described it as "the other half of the Mac's 2020 rebirth," commending the integration with Apple Silicon for enhanced performance and smoother operation of iOS apps on Mac.[61] Ars Technica appreciated the bright, fresh visual style and improvements like the new Control Center, though it criticized reduced window contrast that made some controls harder to discern.[20] Macworld emphasized the convergence with iOS features, such as updated apps like Messages and Maps built with Catalyst, but advised caution for users on older hardware due to potential compatibility hiccups.[62] User feedback echoed these sentiments but highlighted practical challenges during rollout. Many users on newer hardware, particularly Apple Silicon Macs, reported smooth upgrades and appreciated the modern interface's improved navigation and performance boosts, with Safari's faster rendering and privacy tools standing out as daily usability enhancements.[63] However, complaints were common regarding installation issues on older Intel-based models, including bricking of late-2013 and mid-2014 MacBook Pros that resulted in black screens or boot failures, often requiring hardware repairs or reinstalls.[64] Initial beta versions drew criticism for instability, with frequent bugs like app crashes and prolonged update times, though the stable release addressed many of these concerns.[6] Big Sur played a pivotal role in accelerating the transition to Apple Silicon, enabling native support for M1 chips and contributing to rapid adoption among compatible devices.[65]Known security issues
Following its release on November 12, 2020, macOS Big Sur (version 11.0) encountered several security vulnerabilities, primarily addressed through subsequent point releases and security updates issued by Apple. These issues spanned kernel-level flaws, WebKit rendering engine exploits, and other components, with patches focusing on memory corruption, privilege escalation, and arbitrary code execution risks. The signed system volume feature, introduced in Big Sur, served as a key mitigation by protecting core system files from tampering, thereby limiting the impact of some exploits. A notable kernel vulnerability, CVE-2020-27936, involved an out-of-bounds read that could disclose sensitive kernel memory to a malicious application; this was patched in macOS Big Sur 11.1 (released December 14, 2020) via improved input validation.[66] Similarly, WebKit-related exploits posed significant risks, such as CVE-2021-30858, a use-after-free issue that allowed arbitrary code execution when processing malicious web content; Apple resolved this in macOS Big Sur 11.6 (September 13, 2021) with enhanced memory management. Another critical zero-day, CVE-2022-22675, affected the AppleAVD framework (used for audio/video decoding) and enabled kernel code execution through maliciously crafted media files; this was patched in macOS Big Sur 11.6.6 (March 14, 2022) with improved bounds checking.[67] Post-release, macOS Big Sur saw increased reports of phishing campaigns and malware targeting its user base, particularly those transitioning to Apple silicon hardware like the M1 chip, which Big Sur natively supported. Scammers exploited the excitement around Apple silicon by distributing fake update notifications or "security alerts" mimicking Apple's interface to steal Apple ID credentials via typosquatted websites or scareware pop-ups; these incidents surged in 2021-2022, with threat actors pivoting from Windows targets to macOS due to improved browser defenses elsewhere.[68] Malware like variants of Atomic macOS Stealer (AMOS) emerged around 2023, disguising as cracked apps to bypass Gatekeeper and extract data from keychains, disproportionately affecting legacy Big Sur installations on M1 Macs lacking newer protections.[69] Apple's patch timeline for Big Sur included regular security updates to address these and other flaws. For instance, macOS Big Sur 11.2 (January 2021) fixed multiple issues, including CVE-2021-1760 in CoreMedia allowing arbitrary code execution, though it emphasized Bluetooth reliability improvements alongside security enhancements.[70] Subsequent releases like 11.4 (May 2021) patched kernel escalation bugs (e.g., CVE-2021-30703), while 11.6.2 (March 2022) targeted actively exploited vulnerabilities in the kernel and WebKit.[71] Updates continued into 2023, with 11.7.9 (July 24, 2023) resolving privacy leaks in Accessibility and log redaction (e.g., CVE-2023-40442), and the final update, 11.7.10 (September 11, 2023), addressing additional issues like an ImageIO arbitrary code execution vulnerability, before end-of-support on September 26, 2023.[72][73] By 2025, unpatched Big Sur systems face heightened risks from unaddressed zero-days and evolving threats, as no further updates are provided, potentially exposing users to exploits like those in legacy WebKit components without mitigation from newer macOS defenses; additionally, major software like Steam ended support for Big Sur on October 15, 2025, limiting functionality for remaining users.[74][75]Release timeline
Developer and public betas
The developer betas for macOS Big Sur began immediately after its announcement at WWDC on June 22, 2020, with the first build (20A4299v) seeded to Apple Developer Program members for testing the redesigned interface, new Control Center, and core system enhancements. Subsequent developer betas were released roughly weekly through the summer, including build 20A4300b for Beta 2 on July 7, 2020, and continuing with updates like Beta 8 (build 20A5374i) in September, emphasizing stability improvements and bug fixes for features such as Safari tabs and message syncing. By September 2020, builds like 20A5384c in Beta 9 addressed performance optimizations and compatibility issues reported by developers.[76][77][78] Public betas became available starting August 6, 2020, with the initial release (build 20A4299v) open to enrolled users via the Apple Beta Software Program, enabling wider testing of the aquamarine-inspired design and productivity tools like enhanced notifications. Iterative public betas followed, such as Public Beta 3 (build 20A5364e) in August, incorporating fixes for user-reported problems including intermittent Wi-Fi disconnections and battery drain, which were iteratively resolved through network stack refinements and power management tweaks. The beta programs facilitated extensive feedback via Apple's Feedback Assistant portal, with participants contributing to refinements in areas like widget functionality and privacy controls. The final beta seeding occurred in September 2020 with build 20A5384c, transitioning toward the golden master candidate in early October (build 20A2408), which confirmed readiness for the stable release after comprehensive testing.[78]Stable version releases
macOS Big Sur's stable releases commenced with version 11.0, marking the introduction of a redesigned user interface, enhanced Safari browser capabilities, and updates to core apps like Messages and Maps. Subsequent updates focused primarily on resolving bugs, improving stability, and addressing security vulnerabilities, with occasional additions to support new hardware and features. Apple delivered these updates through the Software Update mechanism in System Preferences, ensuring compatibility with supported Mac models from 2013 onward. The following table summarizes the major stable version releases, including key updates where applicable:| Version | Release Date | Key Updates |
|---|---|---|
| 11.0 | November 12, 2020 | Initial public release featuring a new macOS design inspired by iOS, Safari 14 with improved privacy tools like Intelligent Tracking Prevention, and enhancements to Control Center, Notifications, and app icons.[3] |
| 11.0.1 | November 17, 2020 | Bug fixes and security improvements, particularly for early M1 Mac users, including resolutions for Wi-Fi connectivity issues and app compatibility.[79] |
| 11.1 | December 14, 2020 | Introduction of the Shortcuts app from iOS, support for Apple Fitness+ subscriptions, and fixes for stability in Mail and Photos; includes security patches for kernel and WebKit vulnerabilities.[80] |
| 11.2 | February 1, 2021 | Expanded AirPlay support allowing streaming from iPhone or iPad to compatible Macs, additional security updates for WebKit and kernel components, and general bug fixes for performance.[70] |
| 11.3 | April 26, 2021 | Updates to the App Store with family sharing improvements, new emoji support, and security fixes; resolved issues with iCloud and Bluetooth connectivity. |
| 11.4 | May 24, 2021 | Enhanced privacy features in Screen Time, support for Braille displays, and security patches addressing potential arbitrary code execution risks.[71] |
| 11.5 | July 21, 2021 | Introduction of the Legacy Contact feature for Digital Legacy in iCloud, fixes for Shortcuts automation, and multiple security updates for kernel and networking components.[81] |
| 11.6 | September 13, 2021 | Expanded Shortcuts capabilities, new privacy indicators for microphone and camera use, and security enhancements. |
| 11.6.7 | June 9, 2022 | Targeted fixes for Mail app search issues and general stability improvements; primarily security-focused with patches for ImageIO and other libraries.[82] |
| 11.7 | September 12, 2022 | Safari 16 support with security updates for file integrity and kernel protections.[83] |
| 11.7.8 | June 21, 2023 | Security updates addressing vulnerabilities in kernel and other components.[84] |
| 11.7.9 | July 24, 2023 | Supplemental security update addressing accessibility and privacy issues, including improved data redaction in logs.[72] |
| 11.7.10 | September 11, 2023 | Final major security update, patching vulnerabilities in ImageIO, kernel, and WebKit to prevent arbitrary code execution and data leaks.[73] |