What we can say
- Files never leave your device. Documents, signature images and PDF passwords are processed in your browser's memory and are not transmitted to OpenSigner or anyone else (see our Privacy Policy).
- We hold no document data. There is no upload endpoint, no document storage and no document logging, so there is nothing of yours for us to retain, disclose or lose in a breach.
- The seal uses standard cryptography. SHA-256 hashes are computed with the browser's built-in WebCrypto.
- No advertising trackers run on the site.
How this helps with GDPR and HIPAA concerns
Under the EU and UK GDPR, sending a document containing personal data to an online service generally makes that service a processor, which brings contracts, transfer assessments and records of processing. Under HIPAA in the US, a service that receives protected health information for a covered entity is typically a business associate. Because OpenSigner never receives the document, those questions about our handling of your document's contents don't arise in the same way: the processing happens on equipment you control.
What we can't say
OpenSigner is not certified, audited or attested as "GDPR compliant" or "HIPAA compliant", and we don't sign business associate agreements. Compliance depends on how your organisation uses any tool: who may sign what, where signed files are stored, device security, retention, and your own policies. Like any website, our host (Cloudflare) may process connection data such as IP addresses, and Pro purchases involve an email address and payment IDs, as described in our Privacy Policy.
Practical tips
- Store signed files in your organisation's approved system, not in Downloads.
- On shared devices, use a private window so your signature isn't remembered.
- Ask your privacy officer or legal adviser to review the tool against your policies. They can confirm the no-upload behaviour with the browser's network tools or by testing offline.