Short answerOpen WebUI is a self-hosted AI interface. A Custom GPT becomes a custom model (preset) with a base model, system prompt, knowledge and tools. Its docs say ChatGPT-hosted GPTs cannot move over directly. Read the license: it has a branding clause.
| Your GPT | In Open WebUI |
|---|---|
| Instructions | Workspace, Models, Create: name, base model, system prompt (supports variables) |
| Knowledge files | Knowledge (Focused Retrieval or Full Context) |
| Actions | Tools: native MCP (Streamable HTTP), OpenAPI tool servers, Python tools |
| Sharing | Access: Private, specific users or groups, or Public |
License note
Open WebUI's license is BSD-3-style plus a clause that bars altering or removing its branding. Exceptions apply for 50 or fewer end users in a rolling 30 days, with written permission, or with an enterprise license. Its docs say it is not OSI-approved. Read the LICENSE before white-labeling.
Self-hosting is free; the project is very active (a release dated October 16, 2026 at our check). You also pay for your model provider. See open-source vs SaaS and Open WebUI vs LibreChat.
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
Pages describing other companies' products reflect their public documentation on the date shown and can go out of date.