DOCUMENTS
Verify any document, permanently
Prove a file existed exactly as-is at a specific moment. Tamper-proof. Permanent. Your file never leaves your device.
Document verification products
Cryptographic proof that any file or project existed exactly as-is at a specific moment.
Verify a File
Check if any file has been sealed on Attestum. Drop the file — only the cryptographic fingerprint is checked. Your file never leaves your device.
File Verification
Seal any file permanently. Prove it existed in this exact state at this exact time. Your file never leaves your device — only the cryptographic fingerprint is stored.
Project Snapshots
Timestamp an entire project or folder. Build a verifiable development history with cryptographic proof at every milestone.
How document verification works
Your file never leaves your device. Only the cryptographic fingerprint is recorded permanently.
Select
Choose any file on your device
Hash
We compute a unique cryptographic fingerprint — your file never uploads
Seal
The fingerprint is sealed permanently — tamper-proof and independently verifiable
Verify
Anyone can later check their file matches the sealed fingerprint
What can you seal?
Any file, any industry. If you need to prove something existed at a specific moment, Attestum can seal it.
IP Protection
Timestamp code, designs, and inventions. Build a verifiable development history.
Legal Documents
Prove contracts and agreements haven't been altered since signing.
Academic Research
Establish priority of discovery. Prove findings existed at a specific date.
Creative Work
Prove you created music, art, or writing before anyone else.
Compliance
Document timely submission of regulatory filings.
Real Estate
Timestamp inspection reports and property condition documents.
Simple pricing
Free
3 seals/month
Perfect for trying it out
€50
/month Pro
Unlimited seals + everything in Attestum™
Frequently asked questions
Does my file get uploaded anywhere?
No. Your file never leaves your device. Only the cryptographic fingerprint (SHA-256 hash) is recorded permanently.
What file types can I seal?
Any file. PDFs, documents, images, code, spreadsheets, videos — anything up to 100MB.
How do I prove the file later?
Share the verification link. Anyone can drop the file on the verification page — if the fingerprint matches, it's proven identical to what was sealed.
What if I lose the original file?
The sealed proof still exists, but it can only be verified against the original file. Keep your files safe — Attestum proves integrity, not storage.
Is the seal permanent?
Yes. The proof is recorded permanently. The proof is independently verifiable and can't be altered.
Can I seal the same file twice?
Yes. Each seal is a separate timestamped record. Useful for proving a file existed unchanged across multiple dates.
Ready to seal your first document?
3 free seals every month. No credit card required.
Your file never leaves your device · Verify any sealed document for free