iOS 18
i
Developer	Apple
Announced	June 10, 2024 (WWDC)
Initial release	September 16, 2024
Final release	18.x security series (ongoing)
Launch devices	iPhone 16 generation
Preceded by	iOS 17
Succeeded by	iOS 26

iOS 18 is the eighteenth major release of iOS, released on September 16, 2024, with the "Built for Apple Intelligence" iPhone 16 generation — and the vehicle for Apple Intelligence itself, Apple's on-device-first AI system, which arrived not at launch but across a staged drip of point releases beginning with 18.1 that October. Writing tools, notification summaries, Genmoji, Image Playground, ChatGPT integration, and Visual Intelligence rolled out over six months, gated to iPhones with 8 GB of RAM (iPhone 15 Pro and later) — the rollout pace and the gap between the marketing and the shipping features drawing the cycle's sharpest criticism.

The non-AI half was the most customizable iOS ever: home-screen icons placeable anywhere with dark and tinted variants, a rebuilt fully-editable Control Center, app locking and hiding, a standalone Passwords app, RCS messaging support (ending the worst of the green-bubble era's practical pain), and satellite Messages.

Apple Intelligence (18.1–18.4, staged); free icon placement, tinting, and dark icons; redesigned multi-page Control Center with third-party controls; locked and hidden apps; Passwords; RCS; Messages via satellite, scheduled sending, and text effects; a Photos redesign (unified single-view layout — reversed in part after user backlash); Game Mode; hearing-aid mode for AirPods Pro (18.1); and Genmoji/Image Playground (18.2). The notification-summary feature misfiring on news headlines drew a BBC complaint and an 18.3 pause for news apps — the AI era's first public correction.

Every iOS 17 device: iPhone 16 and iPhone 15 generations back through iPhone XR/XS and iPhone SE 2nd/3rd — zero dropped, though Apple Intelligence's 8 GB floor split the fleet into AI haves and have-nots, a two-tier support model new to the platform.

iOS 18 began the platform's AI era and taught its first lessons — staged feature rollouts, capability tiers within supported devices, and the reputational cost of shipping AI marketing ahead of AI features. RCS adoption ended a decade-long interoperability standoff; the customization suite completed the home screen's decade-long thaw. It was also the last iOS numbered in sequence: its successor jumped to iOS 26 under the year-aligned scheme.