iOS 15 is the fifteenth major release of iOS, released on September 20, 2021, with the iPhone 13 generation. Built for the era it launched into, its signature features managed attention and distance: Focus modes filtered notifications and even home screens by context (work, sleep, fitness), notification summaries batched the noise, and FaceTime — the pandemic's video lifeline — gained links, scheduling, grid view, spatial audio, and, remarkably, browser-based joining from Android and Windows.

Live Text made every camera and photo a text scanner via on-device intelligence, and SharePlay synchronized media playback across FaceTime calls. Apple also — briefly — promised users they could stay on iOS 14 with security updates rather than upgrade, an optionality experiment it quietly ended a year later.

Focus modes; Live Text and Visual Look Up; SharePlay (delivered in 15.1); FaceTime links and multi-platform joining; a redesigned Safari with the bottom tab bar (so contested through the beta that Apple made it optional); Maps' 3D city detail; iCloud+ with Private Relay and Hide My Email; Legacy Contacts; and Photos' richer Memories. The 15.4 update added Face ID with a mask — the pandemic's most-requested feature — and 15.6+ settled into a long security tail that ran to March 2025 for the older hardware left behind by iOS 16.

Every iOS 14 device, a third consecutive zero-drop year: iPhone 13 and iPhone 12 generations back through the 2015 iPhone 6s and 2016 iPhone SE — which thereby reached six and seven supported major versions, the records the era is remembered for.

Focus modes made context-aware notification control a standard OS expectation, Live Text normalized ambient OCR, and FaceTime's cross-platform opening marked a rare Apple service reaching across the fence. Its long 15.8.x security tail — patching 2015 hardware into 2025 — closed the A9 generation's decade of software life, the longevity benchmark every platform now gets measured against.