The equivalent of a Gem
| Claude | ChatGPT | |
|---|---|---|
| Closest match | A skill, or a project | A skill. The custom GPT, the old match, retires on December 11, 2026 |
| Format | A folder with SKILL.md, uploaded as a ZIP; a project takes pasted instructions and files | A folder with SKILL.md |
| Where it works | Skills on Free, Pro, Max, Team and Enterprise, with code execution on; projects on every plan, up to five on Free | Standalone skills in the ChatGPT desktop app, Codex CLI and the IDE extension; skills inside plugins also on the web and mobile |
Are Gemini skills and Claude skills the same thing?
They share a format. Google says Gemini skills use the open, Markdown-based SKILL.md format so you can move instructions across tools without being locked in (About the transition from Gems to skills (Workspace admin help)). Claude's skills and OpenAI's skills are folders with a SKILL.md file too, under the open Specification. What differs is around the file: how each app takes the upload, which file types it reads and which tools it can call.
Move a Gem to Claude
As a skill
- Pack your Gem with Skillcase and download "Skill for Claude and ChatGPT". It is a ZIP with a folder named like the skill, holding SKILL.md and every knowledge file you added in references/.
- In Claude, turn on code execution: Anthropic says skills need it.
- Open Customize, then Skills, click +, choose Create skill, then Upload a skill, and pick the ZIP.
As a project
- In Claude, create a project and give it the Gem's name.
- Paste the Gem's instructions into the project's instructions. On the Skillcase page, "Copy the Claude project instructions" puts them on your clipboard.
- Upload the knowledge files to the project. Anthropic says free accounts can have up to five projects.
Move a Gem to ChatGPT
ChatGPT's closest match to a Gem was the custom GPT, and OpenAI is retiring custom GPTs on December 11, 2026 (Custom GPT retirement and migration FAQ). Its way forward is skills and plugins. OpenAI says standalone skills are available in the ChatGPT desktop app, Codex CLI and the IDE extension, and that skills bundled in plugins also work in ChatGPT on the web, desktop and mobile (Build skills).
- Download "Skill for Claude and ChatGPT" from Skillcase and unzip it.
- For Codex, OpenAI's docs list ~/.agents/skills as the folder for your own skills: put the unzipped skill folder there. In the ChatGPT desktop app, Skills in the sidebar lists your skills.
- To share the skill with other people, OpenAI says to package it as a plugin.
What does not move
- Gemini tools. Canvas, Deep Research, Create video, Create music and Guided learning are Gemini features; a skill in Claude or ChatGPT does not bring them along.
- Files from Google Drive. Google says a Gem uses the latest version of a Drive file. A skill holds a copy, so add the current one.
- Your chats with the Gem. They are in Google Takeout, under My Activity, Gemini Apps, not in a skill.
Pack your Gem before December 17
Paste your Gem's name, description and instructions, add its knowledge files, and download one backup that keeps every file, a skill for Gemini with Word files turned into text, and a skill for Claude and ChatGPT. Skillcase marks the files Google's move leaves out. Free, in your browser, and nothing is uploaded.
Questions
What is the Claude equivalent of a Gemini Gem?
A Claude skill or a Claude project. A skill is a SKILL.md folder that Claude uses when a request fits it; a project holds instructions and files that you chat inside. Anthropic says skills are on Free, Pro, Max, Team and Enterprise plans and projects on every plan.
What is the ChatGPT equivalent of a Gemini Gem?
It was the custom GPT, which OpenAI retires on December 11, 2026. OpenAI's way forward is skills and plugins, which use the same SKILL.md folder as Gemini and Claude.
Do I need to move my Gem out of Gemini?
No. Google turns Gems into skills on its own. Moving one is for using the same instructions in Claude or ChatGPT too, or for keeping a copy outside Google.
Sources: Anthropic: Using Skills in Claude; Anthropic: What are projects?; OpenAI: Build skills; OpenAI Help: Custom GPT retirement and migration FAQ; Google Workspace: About the transition from Gems to skills (Workspace admin help); Agent Skills: Specification. Last checked: October 27, 2026. Skillcase is an independent tool by Peak Apps Studio and is not affiliated with OpenAI, Anthropic, Google or Ollama.