Different from classic autocorrect
iOS autocorrect fixes typos in real time, word by word. The automatic proofreading announced at WWDC 2026 operates at a different level: it analyzes written text and flags or corrects grammatical errors, ambiguous constructions, and stylistic issues, similarly to what Grammarly does as a third-party extension. Apple Intelligence makes this native and cross-platform across nearly every text field in the system, as reported by The Shortcut and wi-fiplanet.com in their keynote coverage.
Systemwide: what it means in practice
The key word is 'systemwide'. This is not a feature limited to Mail or Notes — it is a layer that activates in any app using standard iOS and macOS text controls. That includes third-party apps. Users writing documents in Word for iOS, messages in Telegram, or comments in a project management app will receive suggestions without installing anything additional.
Automatic does not mean intrusive (in theory)
Apple has not detailed the exact behavior when proofreading finds an issue: underline, inline suggestion, or separate panel. The model seems to mirror the approach already seen with Writing Tools — subtle, non-blocking — but specifics will emerge from the betas. The privacy question applies here too: does analysis happen on-device, or does it route through Private Cloud Compute for longer passages?