See when your document is actually read, not just downloaded
Open Detection records the real moment of reading: when the recipient opens the file in a secure viewer, with active reading time, scroll depth and an integrity score. Stronger evidence than a manual "I confirm" click, and GDPR-safe by design.
Note: Open Detection only works when zero-knowledge encryption (access code or portal E2EE) is NOT active. With zero-knowledge, our server cannot read the document to detect opening. You choose per transfer: proof of opening or maximum confidentiality.
How Open Detection works
Recipient opens the file
After verification, the file opens in a full-screen secure viewer instead of as a download. PDF, image, audio, video and Office files render directly in the browser, no plugin needed.
We log only what matters
First-render timestamp, active reading time, scroll depth, tab visibility and the originating ASN. IP and device fingerprint are hashed with a server-side salt, never stored in readable form.
Integrity score in your evidence
Five signals combine into a 0-1 integrity score with confidence level (low / medium / high / verified). Automatically added to your verifiable PDF certificate and visible in the sender dashboard.
GDPR-safe by design
We collect the minimum required to prove receipt, and nothing more.
What we record
- First-render timestamp and active reading time
- Scroll depth + interaction count
- Browser, OS and ASN (network owner)
- Hashed IP + device fingerprint (SHA-256 + server salt)
What we never store
- No readable IP address
- No canvas / WebGL / audio-context fingerprint
- No 3rd-party trackers or ad pixels
- No content from the file itself
Why your evidence is stronger
Stronger than a manual "I confirm" click, which can be automated by a script. Each event is recorded on our EU server at the moment of render and then lands in the verifiable PDF certificate, which carries an independent RFC 3161 TSA timestamp.
Which file types work with Open Detection?
Open Detection works for anything that can be rendered in the browser. For files that don't fit a viewer (such as ZIP archives or design-software formats) the recipient can only download. Open Detection evidence is then not available.
Direct in the browser
No server conversion needed
- •PDF documents (.pdf)
- •Images (.jpg, .png, .gif, .webp, .svg, .bmp)
- •Video (.mp4, .mov, .webm, .mkv)
- •Audio (.mp3, .wav, .m4a, .ogg)
Via auto-conversion to PDF
LibreOffice conversion on our EU servers
- •Microsoft Word (.docx, .doc)
- •Microsoft Excel (.xlsx, .xls)
- •Microsoft PowerPoint (.pptx, .ppt)
- •OpenDocument (.odt, .ods, .odp)
- •Apple iWork (.pages, .key, .numbers), best-effort
- •Plain text, CSV and RTF (.txt, .csv, .rtf)
Not supported (download only)
No viewer-render possible, no Open Detection evidence
- •Archives (.zip, .rar, .7z, .tar.gz)
- •Password-protected containers (.zip with password, .gpg)
- •Design files (.psd, .ai, .indd, .dwg)
- •Executables (.exe, .dmg, .app, .deb)
- •Database files (.db, .sqlite, .mdb)
Tip: for mixed transfers (e.g. a ZIP containing PDFs) you're better off sending the PDFs separately, you'll get Open Detection evidence per document.
Ready to make every delivery verifiable?
Open Detection is included in Certified Delivery and Verified Identity.