Send it.
Sign it.
Seal it.
E-signatures for small teams. Every finished document gets a seal cut from its own fingerprint, so anyone can prove it never changed.
- US ESIGN Act
- UETA, all states that adopted it
- SHA-256 on every document
- Append-only audit register
- TLS in transit, encrypted at rest
- Senders verified by a person
Everything a signed document needs.
Six parts, one workspace. No add-ons and no envelope counting.
TabletsEvery document, its state and its signers at a glance.
PressUpload, order the signers, write the note, send.
SealsA gallery of every fired document's seal.
ArchiveFinished records, kept ten years, exportable.
VerifyDrop any copy. It matches the original or it does not.
CertificateSigners, register and both hashes in one sheet.
Press, Seal, Fire
Upload, order, send.
Drop a PDF or Word file. Its SHA-256 is computed in your browser before anything uploads. Add signers in order and send.
- Hashing in your browser
- Signers in order
- Sent
A seal only this file can make.
When the last signer signs, TerraSign fixes the SHA-256 of the final PDF and cuts a seal from it: 64 ticks, 32 dots and a few wedges, all read from the hash. The certificate carries the seal, both fingerprints, every signer and the full register.
- ticks
- 64
- ticks
- dots
- 32
- dots
- file it fits
- 1
- file it fits
Mutual NDA, Brightline Labs
9f2c4e7a1b8d3f60c5e2a9147b6d0e83f1a4c7952e8b0d6a3f9c1e47b2d5a806
Prove a copy is the original.
Drop any copy on the Verify page. Your browser hashes it on the spot, draws its seal and compares it with every fired document. The file is never uploaded.
Try the public verify pageUruk, around 3500 BCE. The first signatures were carved stones rolled into wet clay: personal, impossible to copy without the stone, fixed once the tablet was fired. TerraSign gives every document the same three properties.
Sign here. Watch your seal being cut.
Your browser hashes the signature, your name and the exact time. The seal is cut from that hash. Nothing is sent anywhere.
- Seal
- none yet
- SHA-256
- 64 hex characters
- Made from
- signature, name, time
- Input size
- nothing yet
- Pattern
- picked by the hash
Seal it again without changing anything. The time is part of the input, so the seal changes completely. That is the point: no two impressions can be swapped.
Pricing
Priced per sender. Signers never pay.
Clay
$0per month
For the occasional agreement.
- 3 documents a month
- 1 sender
- Audit register and certificate
- A seal on every fired document
Kiln
Most chosen$14per user, per month
For people who send every week.
- Unlimited documents
- Signing order and reminders
- Personal templates
- Sealed PDF and certificate download
Workshop
$32per user, per month
For teams that share paperwork.
- Everything in Kiln
- Shared team templates
- Bulk send
- Register export and webhooks
US dollars, billed monthly, cancel any time. Signers never pay. Sending opens after a short account verification.
Feature highlights
Signing order
Each signer gets the email when the previous one has signed, or everyone at once.
Reminders
Polite email reminders to whoever is holding things up, on a schedule you set.
Templates
Save fields and signers once, reuse them for every new client.
Bulk send
Send the same document to a list, each copy with its own seal and register.
Signing on a phone
Signers open the link and sign in any modern browser. No account, no app.
Audit register
Time, IP address, device and consent for every view and signature, append only.
Sealed PDF
The finished file with its certificate of completion attached, ready to download.
Seal per document
Cut from the final SHA-256. Same file, same seal. One byte off, a different one.
Verified senders
A person reviews every sender account before it can send, to keep impersonators out.
Email only
Requests, reminders and receipts by email. Never SMS, never marketing you did not ask for.
Frequently asked
Is a TerraSign signature legally binding?
Yes, for most business documents in the United States. Signatures collected with TerraSign are designed to meet the federal ESIGN Act and the Uniform Electronic Transactions Act as adopted by the states. A few documents, such as wills and some court and family-law filings, still need ink. TerraSign does not give legal advice.
What exactly is the seal?
When a document is fired, we compute the SHA-256 of the final file. The seal pattern (borders, panels, motifs) is generated from those 64 hex characters by a fixed rule. The same file always produces the same seal, and any change, even one byte, produces a different one.
Can a fired document still be changed?
No. A fired document is read only. You can void it and send a new version, and the register shows both, but the fired file and its hash never change.
Do my signers need an account?
No. They get an email with a private link, review the document, agree to sign electronically, and sign in any modern browser on a phone or a computer.
How do I prove a copy is the original?
Open the Verify page and drop the file in. Your browser computes its SHA-256 locally and compares it with the certificate. If they match, the seal is identical. The file is never uploaded for this check.
Why does sending need a verification?
A person reviews every new sender account before it can send. It keeps impersonators away from the people you send to, and it usually takes less than one business day.
Where are my documents stored?
In encrypted storage in the United States, in a private folder only your account can read. Transfers use TLS. You can download or delete your documents at any time.
Put your name in clay.
Three documents a month are free. No card, and your signers never pay.
9f2c4e7a1b8d3f60c5e2a9147b6d0e83f1a4c7952e8b0d6a3f9c1e47b2d5a806