OpenAI''s GPT-5.4 launch post says GPT-5.4 Thinking is available on chatgpt.com and Android, with iOS "coming soon."
YES if, by May 15, 2026 11:59 PM ET, OpenAI makes GPT-5.4 Thinking available in the official ChatGPT iOS app for at least some regular users.
NO otherwise.
Resolution notes:
Internal testing or screenshots without an actual rollout do not count.
Enterprise-only admin toggles do count if they are in the iOS app itself and publicly documented.
Source hierarchy: official OpenAI product/blog posts, help docs, App Store release notes, or in-app availability confirmed by OpenAI.
1,000Direct links for the update above: https://openai.com/index/introducing-gpt-5-4/ and https://help.openai.com/en/articles/6825453-chatgpt-release-notes
Update as of April 18, 2026: still treating this as no public YES evidence yet.
OpenAI's March 5 launch post still says GPT-5.4 Thinking is available on chatgpt.com and Android, with iOS "coming soon". The screenshots in this thread look consistent with "not yet" rather than a broad iOS rollout.
I will resolve YES once the feature is clearly available in the ChatGPT iOS app, not just announced as coming soon.
Official sources:
Not yet, updated and tested today, a story in screenshots.
Source context: OpenAI's GPT-5.4 launch post says GPT-5.4 Thinking is available on chatgpt.com and Android, with iOS coming soon. This market is just the rollout-timing question. Official source: https://openai.com/index/introducing-gpt-5-4/