Side by side
0docs vs Fern
Both stand on developer documentation software. Which one you can start free with, which one lets you read the code, and what each costs once you pay.
Free plan APISelf-hostedWeb
0docs offers self-hosted documentation editing, versioning, publishing, and AI-client access. Plan for PostgreSQL and the listed local installation requirements; Ask docs also requires an OpenAI API key.
Visit 0docs Free plan Open source APILinuxMac+3
Fern combines API documentation publishing with client library generation and offers a defined Free plan. Teams considering it should check the free-tier limits and note that self-hosting is reserved for Enterprise.
Visit FernThe facts
| 0docs | Fern | |
|---|---|---|
| Free plan | Yes | Yes |
| Open source | Not published | Yes |
| Runs on | API, Self-hosted, Web | API, Linux, Mac, Self-hosted, Web, Windows |
| Lowest paid plan | Free or on request | Free or on request |
| Plans published | 1 | 2 |
| Maker | Not published | Not published |
| Website | 0docs.dev | buildwithfern.com |
| On developer documentation software | #4 of 27 | #1 of 27 |
0docs: what it does well
- MIT-licensed and free to self-host.
- Supports documentation snapshots and custom domains.
- Built-in MCP endpoint supports read and edit access.
- Media can use PostgreSQL or S3-compatible storage.
- Customizable colors, fonts, sidebar, and block styles.
What to know first
- Requires PostgreSQL.
- Local setup requires Node.js 20+ and pnpm.
- Default upload maximum is 20 MB per upload.
- Without SMTP, reset and invitation links print to server logs.
Fern: what it does well
- Generates API references from several specification formats.
- Includes interactive API Explorer.
- Free plan includes one site.
- Supports SSO, JWT, and OAuth access controls.
- Supports custom domains and version history.
What to know first
- Free plan is limited to one site.
- Free plan has 10 team members.
- Free plan includes 250 AI credits monthly.
- Self-hosting is an Enterprise capability.