Custom GPT migration checklist

Before you migrate

• Confirm who the GPT is for and how it is shared.
• Copy the full instructions to a text file.
• Collect the original knowledge files in one folder and note any outdated ones.
• List every Action: endpoint, authentication and what the instructions tell the GPT to use it for.
• Note conversation starters and the description.
• Write 10 real test questions, including one hard case, and save the current answers.
• Check you have the permissions needed to migrate (creator or admin, GPT published).
• Finish any edits to the original GPT.

During migration

• Move instructions first, then files, then connections.
• Rebuild Actions as a separate task. They do not transfer through OpenAI's migration.
• Re-check the model and capability settings, because they may not carry over.

After migration

• Run your test questions and compare tone, accuracy and refusals.
• Test every connected tool end to end.
• Share with the right people and confirm they can install or access it.
• Tell users where the new version lives and update saved links and onboarding material.
• Keep your backup folder until you are sure nothing was lost.

The common mistakes page covers what usually goes wrong, and testing has the scorecard.