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Is my file private?

Yes—your file is completely private.

Here's how we protect your data:

Client-side hashing: Your file is hashed locally in your browser using SHA-256. The hash is a one-way function—it's mathematically impossible to reverse it back to your original file.
No uploads: We never see, store, or transmit your actual file. Only the hash is sent to our servers for timestamping.
Zero-knowledge proof: Even we can't reconstruct your file from the hash. Only you have the original.

This means you can timestamp sensitive work—drafts, unreleased projects, private notes—without any risk of exposure.

Other Questions

How does timestamping work?

We hash your file locally, anchor that hash on Bitcoin, and generate a verifiable certificate—no uploads, no data exposure.

Is this legally recognized?

Bitcoin timestamps are accepted as admissible digital evidence in multiple jurisdictions. They prove a file existed at a specific time.

Can I verify someone else's proof?

Yes—anyone can independently verify a proof on-chain using our verification page or OpenTimestamps explorer.

Ready to timestamp your work?

Create your first proof in seconds—no signup required for the free tier.