Stirling PDF
Document ManagementA PDF editor and processor with many tools that runs in the browser, on the desktop or on your own server.
Open-source alternative to:

What the free edition leaves out
Scroll sideways to view all columns →The free edition is genuinely usable, but some team or enterprise features need a paid plan. “Not confirmed” means the official pages we read did not say, so we do not guess.
| Feature | Free edition | Details | Source |
|---|---|---|---|
| SSO / SAML | Not confirmed | Two official pages differ: the pricing page lists single sign-on under the Team plan, while the plans table in the docs lists OAuth2/OIDC sign-on on the Free plan and SAML2 as Enterprise only. | Source ↗ |
| Role-based access control | Not confirmed | Roles are not mentioned on the pricing page. | Source ↗ |
| Audit logs | Paid | The pricing page lists audit logs under the Enterprise plan, and the plans table in the docs lists audit logging as Enterprise only. | Source ↗ |
| Multi-user / teams | Free | The plans table lists 5 users on the Free plan and says no more users can be added once the limit is reached; the Team plan allows more. | Source ↗ |
| Backups and restore | Not confirmed | No official page states whether the free edition includes this. | – |
| API access | Free | The plans table in the docs lists the REST API on the Free plan. The same page says API-key calls count toward a monthly processing allowance unless the server has a Team license key. | Source ↗ |
| Support SLA | Paid | The pricing page lists Uptime SLAs under the Enterprise plan. | Source ↗ |
Best for
Individuals and small groups (the free self-hosted plan covers 5 users) that want to edit and process PDFs on their own machine or server instead of an upload-based online tool.
Why choose it over Adobe Acrobat
The free plan lists 60+ PDF tools on the web, desktop and self-hosted, and the project describes itself as private and open source. The server starts from a single Docker command.
Where it falls short
It is open-core. The free self-hosted plan is limited to 5 users. SAML2 sign-in, audit logs, SCIM, air-gapped deployment and uptime SLAs are listed in the Enterprise plan, and the pricing page lists SSO under Team. Folders such as app/proprietary need a paid user license for production use. The company site has moved to stirling.com, so older links may redirect.
Open-source alternative to
- Adobe Acrobat — Stirling PDF edits, merges, converts and signs PDFs, which overlaps with Adobe Acrobat.