If you have built custom assistants in Google Gemini, you have a deadline. On November 17, 2026, Gemini Gems become read-only and Google begins converting them into skills. On December 17, the original Gems and their attached files are removed from Gemini Apps. Anyone who wants to keep a custom assistant needs to back up the instructions and files now and rebuild the setup as a skill before the old copy disappears.
The Key Dates
For personal accounts of users aged 18 and over, the timeline is straightforward. On November 17, the Gem stays visible for reference, but you can no longer use, edit or create it. Converted skills appear as inactive drafts, so you have to switch them on yourself. On December 17, Gems and their files are deleted.
Workspace accounts run on a different schedule. For business, enterprise and nonprofit accounts, Gems move into the Settings panel on November 17 and keep working until at least March 1, 2027, according to Android Police. Workspace education accounts have until June 2027. Google has not announced a date for personal accounts of users under 18.
What Converts and What Does Not
Google's automatic conversion carries over the basics: the name, description, custom instructions and supported knowledge files such as text files, PDFs and images. Everything else is more fragile. Each skill has a 100 MB file limit, and when a Gem exceeds it, the largest files are dropped first. GitHub files, audio and video files, and compressed archives do not transfer. Older Office formats, including .doc, .xls and .ppt files, are also excluded, according to iTechify's migration guide.
Some Gems will not survive at all. Opal and Google Labs-made Gems stop running on November 17. Android Police notes that content from Google Drive and Gemini Notebook cannot be added to skills, and that skills cannot currently be shared with other users. Canvas, Deep Research, Guided Learning, and video and music creation do not work with skills. Users can have up to 100 skills active at once, though they can create more.
Skills also do not sync between the Gemini app and Workspace apps, so a skill you build in one place must be recreated in the other. iTechify's guide notes that the Keep Activity setting must be on for skills to work.
How to Migrate a Gem by Hand
Waiting for the automatic conversion is risky, because it skips files that do not qualify and can produce a weaker copy of a complex setup. Android Police advises starting now, and the manual path is not difficult for a typical Gem.
- Back up the Gem. Open it, copy the custom instructions into a plain text file, and download every knowledge file from the Gem's edit view. Keep the files outside Gemini.
- Name the skill folder. Choose a name in lowercase letters with hyphens, since that format is what the skill system expects.
- Create the skill. Go to Customize, then Skills, then Create, and choose the manual option. Enter the name, description and instructions, and attach the files.
- Add the files carefully. Use the "Add files" option for a few files at a time, because bulk uploads are not supported on that page. Files that are too large or in unsupported formats need to be converted or trimmed first.
- Test in a new chat. Ask the skill a question you already know the answer to and compare the result with the old Gem.
- Save a copy. Download the skill as a SKILL.md zip so you can restore it later, and replace the stored version if you edit it.
For a full export, Google Takeout includes a Gemini option. It is worth running before December 17 if you have many Gems, since Google will delete the files on that date.
Why It Matters
The move reflects a broader change in how Google wants people to package AI behavior. A Gem was a self-contained assistant. A skill is closer to a reusable instruction set that can be loaded into different tasks. That is more flexible, but it also means the migration is not a simple copy. Users who depended on Gems for document-heavy workflows should test their skills against real work before relying on them.
The practical advice is simple. Inventory your Gems this week. Sort them by importance. Back up the instructions and files for anything you use regularly. Rebuild the most important ones as skills first, and test them before the November 17 switch. Leave the rest for later, but do not wait until December to find out which files were dropped.
