
ZeFirst
Prove you were first
0 ratings
Free
In-App Purchases
Rating summary
About
An idea, a design, a manuscript, code, an invention… The day you have to prove you were first, what do you do?
With ZeFirst, in about thirty seconds you get a proof timestamped to the second that nobody can alter, erase or backdate – not even us.
HOW IT WORKS
• Pick a file: document, image, code, audio, any format.
• Your iPhone computes its digital fingerprint (SHA-256): 64 unique characters that can't be reversed.
• Your file never leaves your device. Only the fingerprint is sent.
• ZeFirst records it on a public blockchain, with the exact date and time.
• You get a PDF certificate with a QR code and a verification link to share.
VERIFIABLE WITHOUT US
Every proof carries its references: network, contract, transaction and a link to the public explorer. Anyone can re-verify it from your file, even if ZeFirst disappeared one day.
WHO IS IT FOR?
Writers, creators, designers, developers, inventors, photographers, musicians, students, founders: anyone who shares files and wants to be able to say "this was mine, first".
EVERYTHING YOU CAN DO
• Create a proof of prior existence in a few taps
• Verify a file or a fingerprint, even without an account
• Find all your proofs in "My proofs"
• Download your PDF certificate, with QR code
• Share a verification link
• Co-ownership: record a proof together, with each person's share
• Back up access to your account so you never lose it
• 5 languages, light or dark theme
SIMPLE, NO CRYPTO
Sign in with your e-mail (a one-time code), with Apple or with Google. No password, no cryptocurrency to buy: blockchain fees are on us. Your first 2 proofs are free. After that, refer a friend or buy credits in the app (1 credit = 1 proof).
Your account also works on the web, at zefirst.app.
Good to know: ZeFirst proves that a file existed, exactly as it is, on a given date. It is not a patent or trademark filing. Tip: record your file before sharing it, and keep the original untouched.
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What's New in ZeFirst
1.1.5
October 6, 2026
What's new in 1.1 • Co-ownership: hand each co-author their share. From “Proofs”, open the proof and send them an invitation link; they accept, you confirm. • Sign in with Google or Apple: you now stay signed in after closing the app. • Fixes and improvements.
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Subscriptions & In-App Purchases
$3.99
10 credits
10 blockchain proofs of prior existence




