Create file fingerprints
Your browser creates a unique SHA-256 fingerprint for each file. The files are never uploaded to ProofStamp.
A timestamped record for important files
Give important files a date you can point to.
Choose one or more files. ProofStamp creates a unique fingerprint for each in your browser and prepares one email you can send to yourself or someone else. Nothing is uploaded to ProofStamp.
- Free
- Private
- No registration
- Files stay on your device
- 1Select files
- 2Add context
- 3Email ProofStamp
Step 1
Choose up to 5 files
Your files are read only inside this browser. They are never uploaded to ProofStamp.
Step 2
Add a short description
File fingerprints (SHA-256)
Step 3
Your ProofStamp is ready
Open your email app, check the ProofStamp, and send it.
ProofStamp
1 inbox
Keep the original files.
Keep or share these exact files if they may need to be verified later. The ProofStamp itself does not contain the files.
Check saved files
Do these files match the ProofStamp?
Choose one or more files and paste a fingerprint or the ProofStamp email. Everything is checked in your browser.
You can check one file or all files in the ProofStamp.
How it helps
One ProofStamp for one or more files.
Email one ProofStamp
One email keeps the fingerprints, your description, and the email received time together.
Check later
Verify one file or all of them. A matching fingerprint confirms that file has not changed.
What a ProofStamp does not prove
It does not prove when or where a file was originally created, who made it, whether it was edited before the ProofStamp, or whether its contents are true. The email received time records when the ProofStamp reached the inbox.