Air-gap principle
Document tools for companies handling sensitive data
Contracts, HR records, financial reports: airgap processes PDFs and images entirely on your employees' devices – following the air-gap principle. No file ever leaves the machine. This page explains how that works technically and how your IT department can verify it.
How this differs from conventional online tools
Conventional online tools
- File is transferred over the internet
- Processing by a third party (data processing, Art. 28 GDPR)
- DPA and approval process required
- Copies, logs and caches outside your control
airgap
Your device – everything happens here
No transfer – technically blocked
- The file stays on the device at all times
- No third-party processing – no DPA required
- No copies or logs on remote servers
- Works offline once the page has loaded
How it works technically
All processing runs inside your browser's sandbox: a Web Worker executes the PDF and image engines as WebAssembly – the same technology banking software uses in the browser. The site itself is static; there is no server that could even receive a file.
Architecture · Your device (air gap)
Content-Security-Policy: connect-src 'self'; ← blocks any data transfer to remote servers default-src 'self'; worker-src 'self' blob:; object-src 'none'; …
SELF-HOSTING & SUPPORT
airgap behind your own firewall
- Signed builds on your domain or intranet
- Support with response times and LTS releases
- Compliance documentation for your IT review
The web version here stays free and unlimited.
unternehmen@air-gap.eu · Reply within 24 h
Coming soon: airgap Desktop – with a local LLM, also 100% offline
How your IT department can verify this
Don't take our word for it – check it yourself. Three steps, five minutes:
- 1
Watch the network tab
Open developer tools (F12), select the network tab, process a PDF: after the page has loaded, no further network requests occur – not even to our own domain.
- 2
Inspect the CSP header
Our Content Security Policy technically forbids the browser to send data to remote servers. This is not a policy statement – it's a restriction enforced by the browser itself:
Content-Security-Policy: connect-src 'self'; ← blocks any data transfer to remote servers default-src 'self'; worker-src 'self' blob:; …
- 3
Offline test
Load the page, disconnect Wi-Fi, process a file: every tool keeps working without an internet connection – the definitive proof that no server-side processing exists.
GDPR assessment
- No commissioned data processing: since files never leave the device, we do not process any personal data from your documents. A DPA under Art. 28 GDPR is not required.
- No cookies, no tracking, no user accounts – no consent-requiring data processing takes place.
- Static hosting via an EU-reachable CDN; only technical server logs for delivering the website occur (Art. 6(1)(f) GDPR).
Frequently asked questions from companies
Are our files really never uploaded?
No. All processing happens locally in the browser. The Content Security Policy (connect-src 'self') technically prevents uploads, and the tools demonstrably work offline as well.
Do we need a data processing agreement (DPA)?
No. Since no file leaves the device, no commissioned processing within the meaning of Art. 28 GDPR takes place. There is no processor to sign an agreement with.
Does the tool work behind a corporate proxy and firewall?
Yes. Only the static website is loaded – the same kind of request as any normal web page. After that, no connection is needed. Your IT can whitelist the domain specifically.
Which browsers are supported?
All current browsers: Chrome, Edge, Firefox and Safari (16.4+). No installation and no browser extension required.
Can our IT department inspect the code or behavior?
Yes. The behavior is fully inspectable in the browser (network tab, CSP header, offline test). All code is delivered unobfuscated to the browser and can be analyzed.
Ready to try it?
All tools are free and require no sign-up – test them with a non-critical document while watching the network tab.
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