Stirling PDF
Self-hosted PDF suite with more than 50 operations, running entirely on your own server so documents never leave the network
Quick Overview
| Company | Stirling Tools |
|---|---|
| Category | PDF Tools |
| Headquarters | United Kingdom, United Kingdom |
| Founded | 2023 |
| EU Presence | Yes - United Kingdom; runs wherever you deploy it |
| Data Location | Your own server |
| Open Source | Yes (MIT for core) |
| GDPR Compliant | Yes - you remain sole controller |
| Self-Hosting | Yes - the primary deployment model |
| Main Features | 50+ PDF operations, OCR, redaction, splitting and merging, conversion, form filling, signing, pipeline automation, no telemetry |
| Pricing | Free and open source / commercial Enterprise tier available |
| Best For | Organisations that cannot upload documents to a third-party service |
| Replaces | Adobe Acrobat, Smallpdf, iLovePDF |
Detailed Review
Stirling PDF answers the question every other tool in this category leaves open: what if the documents cannot be uploaded at all. It is an open-source suite you run in Docker on your own server, giving staff a browser-based PDF toolkit while every file stays inside the network.
The operation count is genuinely comprehensive — over fifty, including OCR and true redaction — which is what makes it a credible internal replacement for Acrobat rather than a partial one.
Everything Stays Inside
A single Docker container gives a whole organisation a PDF toolkit at an internal URL. Legal documents, medical records, HR files and unreleased material are processed on your own hardware, with no third-party processor to assess and no retention policy to trust.
For GDPR purposes you remain the sole controller and processor, which is the simplest possible compliance position.
Redaction That Works
Stirling PDF supports true redaction — removing the underlying text rather than drawing a black rectangle over it. This distinction has caused real disclosure incidents in legal and government contexts, and it is a feature many cheaper tools get wrong.
OCR via Tesseract makes scanned documents searchable without sending them anywhere.
Pipelines
Operations can be chained into pipelines and run automatically — watch a folder, OCR everything in it, compress, split by bookmark, output to another folder. For departments processing documents in volume, that turns a manual routine into an unattended process.
Limitations to Consider
Self-hosting is a real requirement: somebody must run and update the container, and for an individual that overhead outweighs the benefit compared with PDF24's free desktop app. The interface is functional rather than polished, the project is young, and some advanced features sit behind the commercial Enterprise tier.
Who Should Use Stirling PDF
Law firms, healthcare providers, public bodies, defence suppliers and any organisation whose documents cannot be uploaded to a cloud service but which still needs staff to have Acrobat-equivalent tooling.
Pros and Cons
Pros
- Documents never leave your network
- 50+ operations including true redaction
- OCR without uploading anything
- Pipeline automation for bulk processing
- MIT-licensed core, no telemetry
Cons
- Requires someone to run and update it
- Interface functional rather than polished
- Some features reserved for Enterprise tier
Alternatives to Stirling PDF
Other European pdf tools worth comparing before you decide:
Smallpdf
Switzerland · 21 PDF tools in one Swiss-hosted workspace
iLovePDF
Spain · Merge, split, compress and sign PDFs in the browser
OnlyOffice
Latvia · Office suite with a full PDF editor and form filling
PDF24
Germany · Free PDF toolkit with a desktop version that works offline
See all European pdf tools or compare them directly against Adobe Acrobat on our alternatives page.
Frequently Asked Questions
No. It runs entirely on your own server, so files are processed locally and you remain the sole data controller — there is no third-party processor involved at all.
A single Docker container. Any small server is sufficient, and there are desktop builds if you prefer to run it on one machine rather than centrally.
Yes, true redaction that removes the underlying text rather than covering it visually — the distinction that has caused real disclosure incidents with weaker tools.
The core is free and open source under MIT. A commercial Enterprise tier adds features such as SSO and advanced access control for larger deployments.