ProofYouWereFirst.com creates a Bitcoin-backed timestamp proving a file existed at a specific moment.

Your file is never uploaded or stored — we hash it locally, anchor that hash to the Bitcoin blockchain, and return a .ots proof file you can verify anytime.

⏱ Fresh proofs (just created): The link won't appear right away — the timestamp must first be submitted and confirmed on the Bitcoin blockchain (this can take several hours).

✅ Confirmed proofs (after ~6 hours): Once confirmed, the link appears showing the Bitcoin transaction ID and block height.

The .ots file is your verifiable proof — it contains cryptographic evidence of your timestamp.

Store it safely. Anyone can later use it with ProofYouWereFirst.com (or any OpenTimestamps tool) to verify your file's authenticity.

No. Only a hash (a digital fingerprint) is processed — your file never leaves your device.

You upload your original file + the .ots proof.

ProofYouWereFirst.com checks the match and confirms:

• ✅ Verified — your file existed at or before a specific Bitcoin block.
• ❌ Not verified — the file or proof don't match.

Once confirmed, a "View on Bitcoin Explorer" link appears on both the timestamp and verification screens.

It opens to mempool.space, showing the Bitcoin transaction anchoring your proof.

We only log anonymous usage data (like "proof created" or "proof verified").

No personal data, no file info. This helps us improve performance and track growth.

Enter your email in the "Notify Me" form in the app.

Submissions are sent securely through Formspree and go directly to our waitlist dashboard.

• Public analytics visualization (proofs over time).
• Optional user profiles for creators.
• Domain integration at ProofYouWereFirst.com.

Yes—courts in major jurisdictions have accepted blockchain timestamps as reliable electronic evidence of a file's existence at a given time. For example: in the U.S., electronic records are admissible under ESIGN/UETA and some states grant presumptions for blockchain records; in the EU, eIDAS recognizes electronic timestamps and Italy equates blockchain storage to a timestamp; in 2025, a French court admitted blockchain proof in a copyright dispute; and China's Supreme People's Court confirmed blockchain data is admissible as evidence.

A timestamp alone proves existence at time X. To prove authorship, link your timestamp to your identity (your account or a signed record) and keep supporting materials (drafts, emails, version history). For critical matters, consider pairing timestamps with formal registrations in your jurisdiction.