Platform: Mac; Apple announcement
Announcement and developer preview, not public availability.
Apple source ↗Apple previewed Big Sur on June 22, 2020, and made it available as a free update on November 12. Its visual changes reached windows, Dock icons, Control Center, and Notification Center. Beyond the new appearance, this generation of macOS accompanied the arrival of the M1 chip in the Mac.

Apple · Big Sur · 2020-06-22 · Apple · Big Sur · 2020-11-12
Safari added a customizable start page, tab previews, and a Privacy Report about blocked trackers. Messages gained pinned conversations, mentions, and inline group replies; Maps added guides and a redesigned layout. The launch announcement still described app privacy summaries as coming later, not as a feature already delivered that day.
Universal 2 let developers combine native Intel and Apple silicon code in one app. Rosetta 2 translated Intel apps for Macs with Apple silicon; it was not a way to run them on an iPhone. Developers could offer iPhone and iPad apps on those new Macs. This did not mean every mobile app was available, or that these apps ran on Intel Macs.
The technical specifications require OS X 10.9 or later, 4 GB RAM, and 35.5 GB free when upgrading from Sierra or later; an earlier release needs up to 44.5 GB. Supported models include MacBook from 2015, Air from 2013, Pro from Late 2013, mini and iMac from 2014, iMac Pro from 2017, and Mac Pro from 2013. The table preserves 11.0.1 on November 12 and 11.1 on December 14, 2020, as selected milestones, not a complete history.
Apple · Big Sur · Technical specifications · Apple · 11.0.1 · 2020-11-12 · Apple · 11.1 · 2020-12-14
Selected releases, not a complete history. Dates follow Apple's release records, not the latest page edit. No builds are included.
ISO date: year-month-day.
Platform: Mac; Apple announcement
Announcement and developer preview, not public availability.
Apple source ↗Platform: macOS
Available to download that day, according to Apple.
Apple source ↗Platform: macOS
Release date recorded by Apple; client update.
Apple source ↗Platform: macOS
Release date recorded by Apple; client update.
Apple source ↗