Custom GPTs are being switched off. Here’s how to keep yours.
OpenAI are retiring Custom GPTs on 11 December 2026. If you’ve built one that you, your team or your clients rely on, you’ll need to migrate it to a plugin before then to keep using it.
The good news is that for most Custom GPTs this takes about two minutes. Your instructions and files come across, and the plugin works the same way inside a normal chat. There are a few things that don’t carry over, though, and it’s worth knowing what they are before you start.
This walkthrough covers the migration itself, how to use and manage the plugin afterwards, and what to check if your GPT uses custom actions.
Nothing breaks today
This is worth saying first. Your Custom GPTs will keep working exactly as they do now until 11 December. If you use them yourself, or you’ve shared them with your team or clients, everyone can carry on using them until that date.
But the date is fixed. OpenAI’s retirement and migration FAQ sets out the timeline, and after 11 December the GPT version stops working. So it’s better to migrate on your own schedule than to leave it until the last week.
How to migrate a Custom GPT to a plugin
In the video we use the tone guide reviewer we built in our earlier Custom GPT walkthrough. The process is the same for any GPT you’ve created.
- Go to your Custom GPTs in ChatGPT. You’ll likely see a notice asking you to migrate your GPTs to plugins by 11 December.
- Click the migrate button. ChatGPT scans the GPT for anything that might not come across. In most cases, everything does.
- Confirm the migration. Your instructions are copied across to a new plugin. It takes a minute or so.
Once it’s finished, you’ll see a message saying the plugin has been migrated successfully.
What happens to the original GPT
In the short term, migrating almost creates a duplicate. You can still open the original GPT and use it by choosing the option to keep using the GPT, but ChatGPT will push you towards the plugin version.
You also won’t be able to edit the original GPT once it’s migrated. From that point on, any changes happen in the plugin.
Using the plugin in a chat
This is the main change in how you work. Rather than opening a GPT from the left-hand side, you use what was your Custom GPT as a plugin inside a normal chat.
Open a new chat, click the plus, and pick your plugin from the list. The chat is now using the plugin. In the video we ask it to check an email for tone, and it responds just as the Custom GPT did. The difference is that it’s running within a standard chat rather than as a separate GPT.
Editing, sharing and downloading your plugin
To manage the plugin, go to Plugins in the left-hand side, then Personal. Your migrated GPT will be listed there. The three-dot menu gives you a few options:
- Manage sharing. This is the one to watch. Sharing settings don’t come across automatically, so if you shared your Custom GPT with anyone, you’ll need to share the plugin with them again.
- Uninstall or delete the plugin if you no longer need it.
- Download it as a zip file. That suggests you’ll be able to move a plugin to other accounts.
- Edit plugin. This opens a chat with a plugin creator skill, where you type the changes you want, such as “change the introduction to say XYZ”. So edits now happen through a normal chat rather than a settings screen.
If your Custom GPT uses custom actions
For GPTs that just have instructions and perhaps some files, the migration is simple. It’s trickier if your GPT uses custom actions, which let it connect to another service.
When you migrate one of these, you’ll see an “unsupported actions” message explaining that features using custom actions won’t work in the plugin. You can still migrate, but those connections to other services will be lost.
OpenAI suggest checking whether the functionality your custom actions provided is available through other apps that can run alongside your plugin. They note this may need custom MCP servers and some technical setup. If you added custom actions in the first place, you’ll probably be comfortable with this. Either way, check that anything your GPT relied on still works in the plugin before you depend on it.
The lesson: keep a copy outside the tool
This isn’t the first time OpenAI have changed the rules, and it won’t be the last. They tend to launch and retire features quite quickly.
A Custom GPT was really a wrapper around the work you’d done: your instructions and your files. What’s being asked now is to move that work into a slightly different container. That’s easy when you still have the material to hand.
So whatever tool you use, keep a copy of your instructions and files somewhere separate. Then if you’re asked to migrate again, or a feature is retired or stops working, you can reuse them elsewhere without starting from scratch.
What to do now
The deadline is 11 December 2026. If you or your clients rely on a Custom GPT, it’s worth migrating it and testing the plugin sooner rather than later. While you’re at it, save a copy of its instructions and files outside ChatGPT.
