Custom GPTs retire Dec 11: migrate yours to a plugin now, and rebuild custom actions first

#What changed

OpenAI plans to retire custom GPTs on Dec 11, 2026 and is moving creators to plugins. Its Help Center FAQ says the change covers all ChatGPT plans, and Enterprise workspaces with an approved deferral get until Feb 11, 2027. When you migrate, the GPT's instructions become a skill inside a new plugin, its knowledge files become reference files, and its connected apps come along as apps. Custom actions, the GPT's selected model, and its sharing settings do not carry over. Your past conversations with custom GPTs stay accessible after retirement.

#Who is affected

Anyone who built a custom GPT, especially ones that call outside services through custom actions or are shared with a team or the public. If you only use someone else's GPT, you can't migrate it yourself; watch the notice on that GPT and the creator's plan for a replacement.

#What to do now

1. Open My GPTs and look for Migrate to plugin. If it isn't there, migration may not be live for your account yet, so check from the account or workspace where you created the GPT.
2. Finish and publish any edits first. Migration uses the latest published version, drafts don't move, and the original GPT turns read-only once migrated. Publishing doesn't require sharing it publicly.
3. Save a few prompts you use often, plus good answers, and compare them against the plugin along with one harder case. OpenAI says the plugin may respond differently.
4. Start early on GPTs with custom actions. Those have to be rebuilt with an existing app or a custom MCP server.
5. Re-share on purpose. The plugin starts private and isn't installed for anyone; making it public takes a separate submission, and in Enterprise workspaces sharing and publishing need the Share plugins and Publish plugins to workspace permissions.

After migrating, @ImplodeXploder reports you can ask the Plugin Creator agent to review and improve your old instructions instead of rewriting them by hand. @DegenOfWallSt has a useful checklist of what moves and what doesn't.

#What is not confirmed

The Oct 26, 2026 stop on creating new custom GPTs appears in the FAQ's Enterprise section as a planned date, and OpenAI marks those Enterprise dates as subject to change; it hasn't said the same cutoff applies to every plan. Migration rolls out to accounts at different times. The Plugin Creator tip is one user's field report and is not independently verified.