Terms of Use
L0GIC Stamp · Last updated: 2026-11-12
- A stamp shows a file existed, unchanged, from the time it was stamped. It doesn't show the file is true, or who made it.
- Your file never reaches us, so we keep no copy. Keep the original and its stamp record yourself.
- Stamp is in beta and free for now. It comes as is, without guarantees.
- Don't use it to break the law, to overload it, or to claim a stamp shows more than it does.
The full terms below are what count.
1. Who we are, and agreeing to these terms
L0GIC Stamp ("Stamp") is a service of L0GIC LLC, a Washington limited liability company ("L0GIC", "we", "us"). By using Stamp, you agree to these Terms of Use. If you don't agree, please don't use it.
2. What Stamp does
When you stamp a file, your browser works out the file's fingerprints on your own device. Only those fingerprints (and the file's name, if you choose to include it) are sent to L0GIC. L0GIC signs them together with the time, asks independent time authorities to sign the time as well, and sends you back a stamp record. Later, anyone with the file and its stamp record can check whether the file is exactly the one that was stamped, and when it was stamped.
How we handle information is described in the Privacy Policy.
3. What a stamp does not show
- That what the file shows or says is true or accurate.
- Who made the file, or who stamped it. Stamp has no accounts. A stamp shows that L0GIC signed the fingerprints at that time, not who asked for it.
- That the file existed before it was stamped.
- That a court, agency, insurer or anyone else will accept it. That is for them to decide.
- Anything about the file's contents. L0GIC never sees your file.
4. Your part: keep the original and the record
We never receive your file and we keep no copy of your stamp record, so we can't recover either one, and we can't look up whether a file was stamped. Keep the original file and its stamp record together, and back them up.
A stamp matches only the exact file. If even one byte changes (re-saving, editing, converting, or sending it through an app that compresses it), it won't match. Some phones hand a web page a converted copy instead of the original; see Help.
5. Beta, price and limits
Stamp is in beta. Stamping is free for now. We may change, limit or stop any part of Stamp. If we start charging, we'll say so on the page before you pay anything. To keep the service available to everyone, the number of stamps one internet address can make in an hour is limited.
6. How long a stamp stays checkable
Checking a stamp needs the file, its stamp record, L0GIC's public keys and the time authorities' root certificates. L0GIC's checking program carries copies of those root certificates, so checking doesn't depend on a computer's own list of trusted roots. It doesn't need any record kept by L0GIC; we keep none. Today, checking is done on this site's Check page: it runs in your browser, and uses L0GIC's server for one part, the time authorities' own signatures. Those signatures are checked as they stood when the authorities signed, so a stamp stays checkable after their certificates expire.
What this can't cover: if a time authority's key, or L0GIC's own key, were ever compromised later, stamps relying on it could become doubtful. If L0GIC's key is ever retired or compromised, we will publish the time after which it is no longer trusted; stamps that a time authority shows were made before that time keep checking as genuine. For files that must stay provable for many years, re-stamping them from time to time is a sensible habit.
7. Acceptable use
You may use Stamp for any lawful purpose. You may not:
- use Stamp for anything unlawful;
- send automated requests in a way that overloads Stamp or gets around its limits, or use it in bulk without our written OK;
- try to forge stamp records, misuse L0GIC's keys, or interfere with Stamp, its server or the time authorities it relies on;
- claim that a stamp shows more than it does (for example that a file is true, who made it, or that L0GIC reviewed it), or present yourself as L0GIC.
8. Not advice
Stamp gives you a technical record. It is not legal, tax, medical or other professional advice, and L0GIC is not your lawyer. Whether a stamp helps in a particular case, and how to present it, are questions for your own attorney or adviser.
9. No warranties
STAMP IS PROVIDED "AS IS" AND "AS AVAILABLE." To the maximum extent permitted by law, L0GIC disclaims all warranties, express or implied, including warranties of merchantability, fitness for a particular purpose and non-infringement. We don't promise that Stamp will always be available or free of errors. Stamping depends on independent time authorities that L0GIC does not control.
10. Limitation of liability
To the maximum extent permitted by law, L0GIC LLC and its members and managers will not be liable for any indirect, incidental, special, consequential or punitive damages, including loss of profits, data, use or goodwill, arising from or related to your use of Stamp.
Our total liability for any claim arising from or related to Stamp will not exceed the greater of the amount you paid us for Stamp in the twelve (12) months before the claim, or fifty U.S. dollars ($50.00).
11. Names and ownership
The L0GIC name and logo belong to L0GIC LLC. Your files are yours; we never receive them. Your stamp records are yours to keep, use and share.
12. Governing law
These terms are governed by the laws of the State of Washington, without regard to conflict-of-law rules. Any dispute will be resolved in the state or federal courts located in Spokane County, Washington, and you agree to the personal jurisdiction of those courts.
13. Changes
We may update these terms. The date at the top shows the latest version. If you keep using Stamp after a change, the new terms apply.
14. Contact
Questions about these terms: support@l0gic.ai