For training centres, academies and anyone who issues certificates
A fake of your certificate? Caught in one click.
Fake certificates are now made with AI in seconds. Yours, any company can check in one click, without calling you and without trusting anyone.
This is a sealed document. Try changing it.
Certificate
Example Academy · awarded to Laura Méndez
CRED-W3B4ZL4W12 September 2026
| Course | Occupational health and safety |
| Duration | 30 hours |
Anyone can check it with its code. If it is revoked, it shows as revoked.
Authentic. This is the document sent on 12 September 2026, down to the last comma.
Altered. This is no longer the document that was sent: its fingerprint doesn’t match.
- Fingerprint of the original
- …
- Fingerprint of this one
- …
The SHA-256 fingerprint is really computed, here, in your browser: that’s how CODEX checks a document, in 3 seconds.
For training centres, schools and academies
The diploma you issued six years ago is still checkable today.
A certificate is worth whatever its verification is worth. If the only way to check it is to phone you, the qualification depends on your phone still being answered a decade from now.
Issue in bulk
A whole graduating class in one go: one holder per line, and every student gets their credential with its own verifiable link.
Employers check it themselves
Whoever is hiring scans the code and sees at once whether the qualification is genuine, whose it is and whether it still stands. No phone call, no sign-up, no trust required.
Revocable, and it shows
If a qualification is annulled, anyone verifying it will see that it was revoked. The correction is public and traceable, not an email someone has to take on faith.
Does any of this sound familiar?
“That’s not what we agreed”
The quote or the terms change version and no one knows which one was right. Here every version is sealed with its date: you can see which one you sent and which one your client accepted.
“It never reached me”
You send a document and later they say they never got it. Here you know when it was opened, and the acceptance or rejection is recorded.
“This degree is fake”
With AI, forging a PDF takes minutes. A sealed document can’t be changed without it showing: if anyone touches a single letter, the check says so.
How it works
Upload or create
Upload the PDF you already have, or create it from a template.
Seal it
Its fingerprint and its date are fixed. From that moment on, any change shows.
Send the link
By email or WhatsApp. Your client opens it, downloads it and checks it without an account.
This certificate doesn’t exist.
And you can’t tell.
An AI generated it in seconds —the institute, the person, the gold seal, even the signatures. To the eye it’s perfect. That’s why an invoice, a contract or a diploma that “looks authentic” no longer proves anything.
The difference between this and a real one is no longer visible: it’s proven. CODEX adds to every document you issue a cryptographic proof —anchored in Bitcoin, which exposes any change— and turns the absence of proof into the warning sign. The real thing carries proof. What doesn’t, distrust it.
Real recording · unedited
This is the check.
Three seconds.
You drop the PDF. Your browser computes the hash and checks it against the Bitcoin chain. The file never leaves your device, and the answer does not come from us.
Recorded against the live site. You can repeat it right now with any document: check a document →
How it works inside
Every document has a unique SHA-256: its fingerprint, which changes if a single letter changes. That SHA-256, anchored in Bitcoin’s public chain with OpenTimestamps, fixes its date: not even we could change it.
The method is an open standard: anyone can check it without AIM CODEX. What sets it apart.
Start today, free
Free, with unlimited documents. From €2.99 a month billed annually, with your brand and your domain.