Custom GPTs are retiring: what it means and what to do

OpenAI is retiring custom GPTs. On December 11, 2026, every custom GPT in ChatGPT, and the page it lives on, stops working. OpenAI's replacement is called a plugin, and it works differently enough that "migrate" undersells the change.

This guide covers all of it: what is going away, every date, what moves across and what doesn't, how to migrate step by step, what to do if you only use other people's GPTs, and where to go if you'd rather not rebuild inside ChatGPT at all. Everything here comes from OpenAI's own help pages, linked as we go, and was checked on October 1, 2026. OpenAI has already moved some of these dates once, so treat the notice in your own account as the final word.

The short version

• Custom GPTs retire on December 11, 2026. On that date, OpenAI says, "custom GPTs and their GPT pages become inaccessible". That covers every plan.
• Your GPTs still work until then. Nothing has been switched off yet for GPTs that already exist.
• Personal accounts can't build new ones. New GPT creation is already off on Free, Go, Plus and Pro.
• The replacement is a plugin. Your instructions become a "skill", your knowledge files become "reference files", and your connected apps come along.
• Some things don't move. Custom actions, past conversations, sharing settings, the people who used your GPT, and the model it was set to use all stay behind.
• After you migrate, the original GPT is frozen. It becomes read-only, and you can't delete it.
• Enterprise workspaces with an approved deferral get until February 11, 2027. Nobody else does.

What exactly is retiring

The whole custom GPT feature, not just the GPT Store. OpenAI's release notes for September 11, 2026 announce it will "retire custom GPTs across ChatGPT plans". In practice that means:

• Every custom GPT, whether you built it for yourself, for your team, or published it publicly.
• Every GPT page. That includes the pages people reach from a share link or from the GPT Store. Old links will simply stop working.
• The GPT builder. It's already gone from personal accounts, and it closes for Enterprise workspaces on October 26, 2026.

Two related changes often get mixed up with this one:

• The Assistants API already shut down, on August 26, 2026. That was a developer product, separate from ChatGPT's GPTs. More on it below.
• Google is making a similar move. Gemini's Gems, its version of custom GPTs, start turning into "skills" in November 2026 for personal accounts.

Every date that matters

• August 2026: personal accounts lose the builder. OpenAI's GPTs help page now says new GPT creation "is not available on personal ChatGPT accounts, including Free, Go, Plus, and Pro." OpenAI didn't publish a date for this, and users started reporting it in August.
• September 11, 2026: the retirement is announced. Enterprise admins got a notice the same day.
• September 22, 2026: migration opens for Enterprise workspaces. That was OpenAI's target, "not a guarantee that the option is available in every workspace". Workspaces that chose delayed banners had an October 1 target instead.
• October 26, 2026: Enterprise workspaces stop creating GPTs. This is a planned date. You can still edit GPTs you haven't migrated.
• December 11, 2026: custom GPTs retire. This is the standard date for every plan.
• February 11, 2027: the deferral deadline. It only applies to Enterprise workspaces that asked for, and were given, an approved deferral.

For plans other than Enterprise, OpenAI says migration "may become available at different times". There is no published date for when the migration option reaches a Plus or Pro account. Watch for the notice in your account.

What a plugin is, and how it differs from a GPT

A plugin is a bundle. It can hold:

• Skills. Reusable instructions, which is where your GPT's instructions end up.
• Reference files. Your knowledge files.
• Connected apps. Links to outside services like Slack or Google Drive.

You build and edit plugins by chatting with a built-in helper called Plugin Creator (you install it from the plugin directory, then type @plugin-creator).

The bigger difference is how you use one. A custom GPT was a place you went: you opened it, and every message in that chat went through its instructions. A plugin is a tool that joins an ordinary chat. You call it with an @ mention, or ChatGPT picks it up on its own when your request seems to match. OpenAI is plain that "the plugin will not necessarily run on every request."

That's why some people in OpenAI's own forum say it isn't an equivalent swap. If your GPT's value was that everything in its chat followed one set of rules, check carefully that the plugin does the same for the work you actually do.

What moves across, and what stays behind

What moves, according to OpenAI's migration FAQ:

• Instructions become a skill inside the new plugin.
• Knowledge files are copied into the plugin's reference files.
• Connected apps are added to the plugin as apps.

What doesn't:

• Custom actions. If your GPT called another service through an action, that stops working in the plugin until you rebuild it. OpenAI says a rebuild "may require a custom MCP server and technical setup", and that a rebuilt version shouldn't be assumed to do everything the original did.
• Your conversations. Past chats with the GPT don't move to the plugin. You can keep using the original GPT until it retires.
• Sharing and users. The plugin starts private. Nobody who used your GPT gets access to the plugin automatically, and a public plugin needs its own submission.
• The model. Whatever model you picked for the GPT doesn't carry over.
• Drafts. Only the latest published version migrates. Unpublished edits are lost. Publishing doesn't mean making it public, though: you can publish it privately.

Two things OpenAI hasn't addressed yet: conversation starters and capability toggles like web search or image creation. Check them by hand after you migrate.

Can you export a GPT?

Not directly. OpenAI doesn't offer a way to download a GPT's setup as a file. The in-product migration is the only official route. That's why the first step below is making your own copy.

You can export your chat history, on Free, Go, Plus, Pro and eligible Edu accounts: go to Settings, then Data controls, then Export data. The export can take up to 7 days, and the download link expires 24 hours after it arrives. Self-service export isn't available on Business, Enterprise or Healthcare workspaces; ask your workspace owner instead.

If you built GPTs: how to migrate, step by step

1. Make your own copy first. This is our advice, not OpenAI's, and it doesn't take long. Copy the instructions into a document. Download every knowledge file. Write down any custom actions and what they connect to. Save five to ten requests you use often, with the answers you were happy with. Once you migrate, the original is read-only; once it retires, it's gone.
2. Finish and publish any edits. Migration takes the latest published version only, and you can't edit the original afterwards. You can publish privately.
3. Migrate. When the option reaches your account, go to My GPTs, choose Migrate to plugin on the GPT, review the details and follow the steps. Only the person who created the GPT can do this (or, in an Enterprise workspace, an admin).
4. Test it against your saved requests. Run the ones you saved in step one, plus at least one harder case. OpenAI suggests checking that the plugin picks the right skill, uses the right reference files, answers in the format you need, and has the tools it needs. A migrated plugin "may respond differently", so compare the answers side by side.
5. Rebuild custom actions. Check first whether an existing app in the plugin directory already does the job. If not, a rebuild usually means a developer and a custom MCP server.
6. Share it, then move people over. The plugin starts private. Share it, ask one person to install and test it, and only then point everyone else at it.

Leave more time than you think for any GPT with actions. Everything else is mostly copy and check. Actions are real rebuild work.

If you use someone else's GPT

You can't migrate a GPT you didn't create, and you don't need to. What you do need to know:

• Check the notice on the GPT. Creators have been asked to point users to a replacement.
• Your access doesn't carry over. Being able to use a GPT today "does not guarantee access to its replacement plugin". You may need the creator to share it with you.
• Where it was made matters, not your plan. Public GPTs made in Enterprise workspaces follow the Enterprise timeline, even if you use them from a personal account.
• Save what you need from it. If you rely on a public GPT for something specific, write down what you ask it and what good answers look like, in case no replacement appears.

If you run a Business or Enterprise workspace

Admins have the most to organize, and a few details only apply to you:

• List what your team relies on. Which GPTs, who built them, who maintains them, and who needs access to each replacement.
• Check plugins are switched on. Migration won't appear if plugins are disabled, if the GPT isn't published, or if the person trying isn't its creator or an admin.
• Sharing and publishing are separate permissions. Sharing a plugin with people needs "Share plugins". Putting it in the workspace directory needs "Publish plugins to workspace".
• Watch the cost. On Enterprise, using a migrated GPT without apps in normal chat has no extra cost. Creating and editing plugins happens in Work or Codex, and actions in Work use credits.
• Bring security in early for actions. Rebuilt integrations need the same review as any new connection to your systems.
• Standard admin emails use the standard dates. If your workspace has a deferral, confirm your real timeline with your OpenAI account team.

If you built on the Assistants API

This one is already over. The Assistants API shut down on August 26, 2026, a year after OpenAI announced it. The replacement is the Responses API with the Conversations API, and OpenAI's migration guide maps the old pieces to the new ones. If a tool you pay for was built on it and still works, it has already moved. If it stopped working in late August, that's why.

The problems people are running into

• "I don't see a migration option." It may not have reached your account yet, plugins may be switched off, or you may be signed in to a different account from the one that built the GPT.
• "The plugin doesn't kick in." Plugins aren't guaranteed to run on every request. Call it with an @ mention when it matters.
• "The answers changed." The model didn't carry over, and the instructions now sit inside a skill rather than running the whole chat. Test before you rely on it.
• "My integration broke." Custom actions don't migrate. See step five above.
• "My users can't find it." They lost access at migration and need it shared again.
• "I can't delete the old GPT." After migration, creators can't. It disappears at retirement.
• "What about GPT Store earnings?" OpenAI hasn't said anything about builder payouts or usage stats. If you depended on either, ask OpenAI directly.

Migrate, rebuild or move: which one is you

Migrate if your GPT is instructions plus a few files. The built-in migration covers it, and your main job is testing.

Rebuild if it depends on custom actions. Budget for developer time, and check the plugin directory first for an app that already connects to the service.

Move if the GPT was a workaround for a job that isn't really a chat job. That's usually true when the same task repeats many times, for different people or clients, and the result needs checking or sign-off by someone else. Rebuilding that as a plugin keeps the workaround going.

If you do decide to leave ChatGPT for this, these are the closest equivalents elsewhere:

• Claude has Projects, workspaces with their own instructions, files and chat history, and Skills, reusable instructions it loads when relevant. Projects are on every plan, with five on the free plan.
• Gemini is moving from Gems to skills starting in November 2026 for personal accounts, and in 2027 for work and school accounts. Google says it will recreate your Gems as skills automatically.
• Microsoft 365 Copilot has agents you can build with instructions and files from SharePoint or OneDrive, aimed at work accounts.
• Perplexity has Projects: shared workspaces with instructions, files and connected tools.

Notice the pattern. Microsoft shut down custom GPTs in Copilot Pro in July 2024, three months after launch, and deleted the ones people had made. OpenAI is retiring its version now. Google is reshaping its own. Every one of these is a feature inside someone else's product, and features change. Whatever you move to, keep the thing that matters in a form you own.

What agencies should take from this

If your agency built one custom GPT per client, you know the setup: paste the client's brand guide in, add a few of their posts, and you had a "client voice" GPT the whole team could use. For a lot of teams it was the best option available, and it worked well enough.

The retirement shows the weak spot. That client's voice lived in a chat feature. When the feature changes, the voice has to be rebuilt, retested and re-shared, and in Microsoft's case, it was deleted. As Ragan put it, getting a GPT to sound like your CEO "was not a quick afternoon project."

So whatever you do with the GPTs themselves, keep a record for each client that doesn't depend on any one tool:

• Their real published posts. Five to ten is plenty. These show how they write far better than a style guide describing it. We explain why in how AI content repurposing actually works.
• Words they use, and words they'd never use. Including the ones they've corrected you on.
• Every change they've asked for. "Don't call us a firm." "Never mention pricing." These are gold, and they usually live in one person's chat history.
• Approved examples for each format. A LinkedIn post they signed off. A newsletter section they liked.
• Who signs off. And how quickly they usually reply.

That record is what makes a new tool work on day one. It's also the thing a chat window never kept well for more than a few clients, which is the subject of why ChatGPT breaks down when you're managing 20 clients.

Where GoMimic fits

If your custom GPTs were one per client, used to turn each client's published posts into LinkedIn posts, newsletter sections, threads and the like, that job doesn't have to be rebuilt as a plugin. That's the job GoMimic is built for.

• The client is the unit, not the chat. You add a client once. Every post you run for them starts from their record, whoever on the team is doing it.
• The voice comes from their real writing. GoMimic learns each client's habits from their own published posts, and a habit only counts once it has shown up in three of them. Nobody pastes a brand guide into a chat.
• One post in, the formats you pick out. Paste a published post and pick the formats that client needs, from LinkedIn posts to newsletters, X threads, Google Business Profile posts and more. The choice is remembered for next time.
• Sign-off is built in. Send the set to your client, who approves it from a link with no login. We covered the process in how to get client sign-off without chasing.
• It's not a feature inside a chat product. Your clients, their voice and their history live in one place that doesn't change shape when a chat product does.

It won't replace every GPT you have. A GPT that answers questions about your own contracts, or checks a spreadsheet, belongs in a plugin or one of the tools above. But for the client content work, you can try it on one of your own client posts without creating an account, and see whether the result sounds like them.

Questions people are asking

Will my custom GPTs stop working before December 11?

No. OpenAI says existing GPTs "remain usable until the retirement date". The exception is an Enterprise workspace given a later date by an approved deferral.

Do I have to migrate?

No. If you don't, the GPT simply stops working at retirement. Migrate only the ones worth keeping.

Can I still edit my GPT?

Until you migrate, yes. After you migrate, the original is read-only, and changes go into the plugin.

Will my chat history with a GPT disappear?

Your conversations don't move into the plugin. If you want a copy, request an export from Settings, then Data controls, before December 11. OpenAI's help page says the export includes your chat history, but doesn't say specifically whether chats with GPTs are in it, so check the file.

Is the GPT Store closing?

GPT pages, including store listings, become inaccessible when GPTs retire. Public discovery moves to the plugin directory, where each public plugin needs its own submission.

Are plugins available on the free plan?

OpenAI says the plugin directory "is available across ChatGPT plans", but that installing or using a given plugin depends on your plan, workspace, role and region. Check the directory in your own account.

Can Plus and Pro users migrate their GPTs?

OpenAI says the change "affects all ChatGPT plans" and that migration access "may differ by account or workspace". It hasn't published a date for personal accounts. Follow the notice in your account.

What happens to the GPTs I use but didn't build?

They retire on the same date. Look for the creator's replacement, and expect to need access to it shared with you.

Is this the same as the Assistants API shutdown?

No. That was a developer product, and it shut down on August 26, 2026. Custom GPTs are the ChatGPT feature, and they retire on December 11, 2026.

I'm an agency with a GPT per client. What's the fastest safe move?

Copy each GPT's instructions and files out this week, and add the client's real published posts and change requests to the same folder. Then decide per client: migrate to a plugin, or move the content work to a tool built around clients rather than chats.

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