Authenticity is infrastructure.
It shouldn’t be for rent.
Today, proving a file is genuine means paying to join a private trust list: a members-only club that rents you credibility by the year and makes verification depend on one vendor and one PDF reader. That isn't trust. It's a tollbooth on something the world needs freely.
Every day, decisions turn on documents, a contract, a diploma, an invoice, a permit, a medical record. And every day it gets easier to fabricate one that looks perfect. The usual answer is to trust a logo: a green badge, a paid seal, a name you’re supposed to recognise.
We think that’s backwards. Trusting a badge means trusting whoever sells the badge. Real proof shouldn’t need a middleman, a fee, or your faith in a brand. It should be something anyone can check for themselves, for free, forever.
Proof that a document is real should belong to everyone.
What we stand on
Authenticity is infrastructure
Knowing a document is genuine shouldn't depend on paying a vendor, trusting a brand, or hoping a server stays online. It should be a property of the document itself, checkable by anyone, anywhere.
Proof that stands on its own
A seal is permanent proof, issued once, yours forever. Verification is keyless and public, so anyone can check any seal, free and instantly. Even if this project vanished, every seal ever made stays verifiable.
Open, all the way down
The code is open source. The formats are open standards, PAdES signatures, X.509 certificates, OpenTimestamps. The anchor is a public ledger. Nothing here is ours to lock up.
Free, and it stays free
Sealing is free. Verifying is free. It will not become free-for-now-then-metered. Sustainability, if we need it, comes from optional hosted convenience, never from charging for the truth.
Run by a foundation, not a startup.
Let’s Seal is stewarded by Experimental Open Works, a home for free, public-benefit infrastructure, the way ISRG runs Let’s Encrypt. No investors, no exit, no plan to enclose it later. It’s built to outlive us.
See how it holds up
Proof, not trust. That’s the point. Read exactly how a seal is made and how anyone can check it.