Does this replace a wet signature or a notary?

No. A seal proves the document is authentic, unaltered, sealed by your firm, and existed by a date — integrity, issuer, and time. It doesn't witness a person's identity the way a notary does. It's the cryptographic layer beneath whatever signing or witnessing your matter requires.

Can the other side verify without an account?

Yes. Verification is public and free — opposing counsel or a court opens the proof link, or runs the standard tools offline. The proof carries everything they need.

What happens if the document is amended later?

Seal the amended version too. Each version gets its own seal and timestamp, so the record shows exactly what existed when — useful when a dispute turns on which draft was in force.

Is it standards-based and durable?

The seal is a standard PAdES/X.509 signature and an OpenTimestamps Bitcoin anchor — the same primitives courts and auditors already recognise, delivered inside the PDF and verifiable for years.

Seal and verify legal documents

Executed agreements, deeds, opinions, and court filings that prove their own authenticity — sealed to a published root, timestamped on Bitcoin, and verifiable by any court, counterparty, or regulator. This is how a legal document stands on its own.

For solicitors, barristers, in-house counsel, paralegals, and ediscovery teams.

Open the app Developer docs

What a seal proves

Four guarantees, in law & legal

The executed version is the version

A changed clause, amount, or date — a single altered byte — fails verification instantly. What was signed is what verifies.

A named signer of record

Every seal names the firm that issued it, chaining to a published root. Not a vague “verified” badge — a specific certificate.

Fixed in time

An OpenTimestamps proof on Bitcoin pins the moment the document existed — decisive for deadlines, priority, and which version came first.

Checked by anyone

Opposing counsel, a court, or a notary confirms the proof at a permalink — free, and standing on public infrastructure rather than on us.

How it works

From your file to a proof anyone can check

The same pipeline every time — the seal and the timestamp travel with the file, so the proof is self-contained.

Your file

Your signed PDF

Seal

Signed over every byte · PAdES

Anchor

Bitcoin timestamp + public transparency log

Proof page

A permanent /d/… link travels with the file

Anyone verifies

Free, public, offline-capable — for anyone

The proof travels inside the file. Verification stands on the published root, the transparency log, and the Bitcoin ledger — so a court, a bank, or a counterparty can check it independently, forever.

Step by step · the web app

Seal it in the app — no setup

1
Sign in as your firm
Open app.letsseal.org and sign in. Your firm gets its own certificate authority the first time — every seal you issue chains to it.
2
Upload the executed PDF
Drop in the signed agreement. Let's Seal seals the whole file with your firm's certificate as a PAdES signature covering every byte.
3
It's anchored for you
The file's fingerprint is timestamped on Bitcoin and written to the public transparency log. You get back a normal PDF that also verifies.
4
Share the proof link
Every sealed document has a permanent proof page. Put the link in the closing bundle; anyone opens it to confirm the document is authentic and unchanged.

Step by step · the CLI

Automate it from your terminal or CI

The sealbot CLI does the same thing, scriptably — one command per file, straight into your pipeline.

# Seal an executed agreement under your firm's certificate
$ sealbot seal settlement-agreement.pdf --org examples
sealed   settlement-agreement.pdf
  sha256 9f2c4e…a41b
  proof  https://letsseal.org/d/9f2c4e…a41b
  anchored to Bitcoin · recorded in the transparency log

# Anyone confirms it — public, free, offline-capable
$ sealbot verify settlement-agreement.pdf
✓ authentic · unaltered · sealed by Let's Seal Examples

Sealing uses your firm's key — an API key or your own instance. Verifying is public: opposing counsel or a court runs it against the portal, or offline with a standard PAdES validator.

Full CLI & API reference

See a real proof

A sealed settlement agreement

Open the proof page the way opposing counsel would: it shows the document is authentic, unaltered since sealing, sealed by the issuing firm, and timestamped on Bitcoin.

Open the live proof

A real document, sealed under the “Let’s Seal Examples” organisation.

Common documents

What you’ll seal

Contracts & deeds
Legal opinions
Engagement letters
Wills
Affidavits
Powers of attorney
Court filings
Disclosure bundles
Settlement agreements

Questions

Straight answers

Does this replace a wet signature or a notary?: No. A seal proves the document is authentic, unaltered, sealed by your firm, and existed by a date — integrity, issuer, and time. It doesn't witness a person's identity the way a notary does. It's the cryptographic layer beneath whatever signing or witnessing your matter requires.
Can the other side verify without an account?: Yes. Verification is public and free — opposing counsel or a court opens the proof link, or runs the standard tools offline. The proof carries everything they need.
What happens if the document is amended later?: Seal the amended version too. Each version gets its own seal and timestamp, so the record shows exactly what existed when — useful when a dispute turns on which draft was in force.
Is it standards-based and durable?: The seal is a standard PAdES/X.509 signature and an OpenTimestamps Bitcoin anchor — the same primitives courts and auditors already recognise, delivered inside the PDF and verifiable for years.

Start sealing law & legal documents

Free and open. Seal in the app, automate from the CLI, and hand anyone a proof they can verify themselves.

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