Can I still use GPT-4.5 anywhere after the ChatGPT retirement?

GPT-4.5 is still available through the OpenAI API and is unaffected there — only the ChatGPT product dropped it on June 26, 2026. API customers who pinned the gpt-4.5 model id keep the same endpoint and pricing; OpenAI's deprecations page tracks any future API-side change separately from ChatGPT lifecycle events.

What happens to my old GPT-4.5 chats and custom GPTs?

Every GPT-4.5 conversation and every custom GPT that was set to GPT-4.5 automatically switches to GPT-5.5 inside ChatGPT. Existing chat history stays intact and new turns answer with GPT-5.5; custom GPT owners do not need to migrate manually, but any system prompt tuned specifically for GPT-4.5 style will now be interpreted by the newer model.

Why did OpenAI retire GPT-4.5?

OpenAI's release note frames the GPT-4.5 retirement as continuing to remove older models with limited usage in ChatGPT so the company can focus capacity on newer, more capable models. GPT-4.5 had become a niche choice inside ChatGPT after GPT-5.5 Instant got the June 24 quality upgrade, and pulling it frees inference fleet for the GPT-5.6 Sol preview shipped two days later.

Is any GPT-4 model still inside ChatGPT after this?

No — GPT-4.5 was the final GPT-4 line model living inside ChatGPT, so the June 26 retirement closes out the GPT-4 era there. GPT-4o, GPT-4.1 and GPT-4.1 mini were already removed earlier in 2026 alongside o4-mini; only GPT-5.x and o-series reasoning models remain selectable in ChatGPT going forward.

OpenAI · 2026-06-26 · major

GPT-4.5 retired from ChatGPT — end of the GPT-4 era in the app

OpenAI removed GPT-4.5 from ChatGPT on June 26, 2026, including from custom GPTs. Existing GPT-4.5 conversations continue on GPT-5.5. The change applies only to ChatGPT — the OpenAI API still serves every GPT-4 model unchanged.

ChatGPT branding banner accompanying TechRadar's GPT-4.5 retirement report — TechRadar / Future

OpenAI quietly switched off GPT-4.5 in ChatGPT, ending the GPT-4 line inside the product while leaving the API untouched.

Quick facts

Maker	OpenAI
Retired from	ChatGPT (including custom GPTs)
Effective	June 26, 2026
Existing chats	Auto-migrated to GPT-5.5
API status	Unchanged — GPT-4.5 still served via API
Sunset window	30 days, announced May 28, 2026
Next planned retirement	OpenAI o3 from ChatGPT, August 26, 2026

What is it?

GPT-4.5 was removed from ChatGPT on June 26, 2026, including from every custom GPT that had it pinned. The change applies only to the ChatGPT product — the OpenAI API still serves GPT-4.5 — and follows a 30-day sunset window announced on May 28. With this removal, no GPT-4 line model remains selectable inside ChatGPT.

How does it work?

OpenAI's ChatGPT release notes say existing GPT-4.5 conversations continue, but every new turn now answers with GPT-5.5; custom GPTs that named GPT-4.5 in their configuration silently fall back to the same replacement. The retirement was previously scheduled in OpenAI's deprecations doc, alongside an August 26, 2026 plan to retire o3 from ChatGPT on a 90-day window.

Why does it matter?

GPT-4.5 was the last GPT-4 line model inside ChatGPT, so retiring it closes the chapter that opened with ChatGPT-4 in 2023. Custom GPT owners who tuned prompts for the older model's behaviour now get GPT-5.5 by default; teams that need the GPT-4.5 personality at all have to move to the API and pin the gpt-4.5 model id explicitly.

Who is it for?

Custom GPT owners, ChatGPT power users, and teams still pinning GPT-4.5 behaviour

Frequently asked questions

Can I still use GPT-4.5 anywhere after the ChatGPT retirement?: GPT-4.5 is still available through the OpenAI API and is unaffected there — only the ChatGPT product dropped it on June 26, 2026. API customers who pinned the gpt-4.5 model id keep the same endpoint and pricing; OpenAI's deprecations page tracks any future API-side change separately from ChatGPT lifecycle events.
What happens to my old GPT-4.5 chats and custom GPTs?: Every GPT-4.5 conversation and every custom GPT that was set to GPT-4.5 automatically switches to GPT-5.5 inside ChatGPT. Existing chat history stays intact and new turns answer with GPT-5.5; custom GPT owners do not need to migrate manually, but any system prompt tuned specifically for GPT-4.5 style will now be interpreted by the newer model.
Why did OpenAI retire GPT-4.5?: OpenAI's release note frames the GPT-4.5 retirement as continuing to remove older models with limited usage in ChatGPT so the company can focus capacity on newer, more capable models. GPT-4.5 had become a niche choice inside ChatGPT after GPT-5.5 Instant got the June 24 quality upgrade, and pulling it frees inference fleet for the GPT-5.6 Sol preview shipped two days later.
Is any GPT-4 model still inside ChatGPT after this?: No — GPT-4.5 was the final GPT-4 line model living inside ChatGPT, so the June 26 retirement closes out the GPT-4 era there. GPT-4o, GPT-4.1 and GPT-4.1 mini were already removed earlier in 2026 alongside o4-mini; only GPT-5.x and o-series reasoning models remain selectable in ChatGPT going forward.

Try it

Open Settings → Customize ChatGPT and reselect a model for any custom GPT that was on GPT-4.5