About

Your files and text stay with you

When you choose a file or enter text, your browser calculates its fingerprint/hash. Only that fingerprint is sent to timeseal.net and is published for everyone to find. The file or text itself never leaves your computer.

Frequently Asked Questions

What do I need to prove that data existed at a certain date and has not changed since?

You need three things: your original file or text, unchanged; the daily txt file from timeseal.net that contains its hash; and the blockchain transaction that holds the SHA-256 hash of that daily file. Anyone can then recalculate the SHA-256 of your data and find it in the daily file, recalculate the SHA-256 of the daily file and see that it matches the hash written in the transaction. The date and time of the block prove when it existed. If even one bit of your data had changed, its hash would no longer match.

Do I need timeseal.net to prove that data existed at a certain date and has not changed since?

No. Once you have saved your data and a copy of the daily txt file, the proof depends only on the public blockchain and the standard SHA-256 method. Anyone can check it with common tools and a public blockchain explorer, even if timeseal.net no longer exists. We recommend downloading and keeping the daily txt file together with your data.

Will more blockchains be supported besides Bitcoin?

Yes. Bitcoin, Ethereum and Cardano are supported now, and World Mobile Chain is coming soon.

Disclaimer of Warranty

TimeSeal (timeseal.net) is provided free of charge, "as is" and "as available," without any warranty of any kind, express or implied.

To the fullest extent permitted by law, timeseal.net ("we") disclaims all warranties. That includes warranties of accuracy, reliability, availability, fitness for a particular purpose, and non-infringement.

No guarantee of results. We do not guarantee that: the service will be available, uninterrupted, secure or error-free; your fingerprint will be included in a daily file; a daily file will be recorded on the Bitcoin blockchain at a particular time, or at all; daily files will remain available for download in the future; a timestamp made with TimeSeal will be accepted as evidence by any court, authority or other party, or will prove what you need it to prove.

Your responsibility. Your file never leaves your device, so we never have a copy of it. You alone are responsible for keeping four things: your original, unchanged file, its fingerprint, the blockchain transaction id and the daily file that contains that fingerprint. If you lose any of them, you may not be able to prove anything, and we cannot recover them for you.

Systems we don't control. TimeSeal relies on the blockchain network, your browser and other systems outside our control. We are not responsible for their delays, changes or failures.

No legal advice. Nothing on this website is legal advice. If you plan to rely on a timestamp in a legal matter, ask a lawyer.

Limitation of liability. To the fullest extent permitted by law, we are not liable for any damage of any kind arising from your use of the service, or from being unable to use it. This includes loss of data, loss of evidence and loss of a legal claim. Nothing in this disclaimer limits liability that the law does not allow to be limited, including liability for intent or gross negligence. It also does not limit any rights you have as a consumer under mandatory law.

Changes. We may change, suspend or stop the service at any time without notice.