Short answerAll three save instructions and files for reuse. Custom GPTs are being retired, Gems are transitioning to skills, and Claude Projects are described by Anthropic as available on all plans. Only Custom GPTs have Actions.
| Custom GPT | Gemini Gem | Claude Project | |
|---|---|---|---|
| Instructions | Yes | Yes | Yes (custom instructions) |
| Knowledge | Files | Device, Drive, NotebookLM | Files (30 MB each; PDF, DOCX, CSV, TXT, HTML and more) |
| Outside connections | Actions | Not verified | Not verified on the pages read |
| Sharing | Share the GPT | Viewer/editor, by email or link on personal accounts | Team and Enterprise plans |
| Status | Planned retirement | Transitioning to skills | Available on all plans (5 projects on Free) |
See each in detail: Gemini, Claude, GPT dates.
Check your GPT before you move it
Paste your instructions, file names and Actions schema into the free checker. It runs in your browser and builds a portable bundle. Nothing is uploaded.
Open the free checkerRelated guides
Sources
- Google Gemini Help: Create and use Gems
- Google Gemini Help: Gems and skills transition
- Claude Help Center: What are projects?
- Claude Help Center: Uploading files to Claude
- OpenAI Help Center: Custom GPT retirement and migration FAQ
Pages describing other companies' products reflect their public documentation on the date shown and can go out of date.