A timestamping proof standard

OpenTimestamps aims to be a standard format for blockchain timestamping. The format is flexible enough to be vendor and blockchain independent.

Stamp

Data to timestamp

Drop here a document
Or click to select one

Max file size is 100MB

The hash is calculated on your browser preserving your privacy. More. Timestamping proof download will start automatically after pressing the button

52%

Hashing

Success!

OpenTimestamps receipt created and download started

Failure!

To stamp you need to drop a file in the Data field

Verify

Timestamped data

Drop here .ots receipt
Or click to select one

In-browser verification is to be considered for testing purpose only.
For proven security system use OpenTimestamps client

52%

Hashing

Success!

OpenTimestamps receipt created and download started

Failure!

To stamp you need to drop a file in the Data field


How it Works?

A timestamps proves that some data existed prior to some point in time, OpenTimestamps defines a set of operations to describe a timestamp which could be done in different way. At the time of writing timestamping on the Bitcoin blockchain is supported. More.


Anyone could realize a timestamp with the permissionless blockchain by paying the transaction fees, for your convenience we offer calendar servers that perform this operation for you. These servers are free to use and they don't require any registration or api key.

Python

Javascript

Java


$ git clone https://github.com/opentimestamps/opentimestamps-client
$ cd opentimestamps-client
$ pip3 install -r requirements
$ ./ots stamp my-file

          
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$ npm install -g javascript-opentimestamps
$ ots-cli.js stamp my-file

          
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$ git clone https://github.com/opentimestamps/java-opentimestamps
$ cd java-opentimestamps
$ mvn install
$ java -jar target/OtsCli.jar stamp my-file

          
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Members

Repositories

Client

Client tool to perform stamping of files through a calendar server and to verify OpenTimestamps proof

opentimestamps-client

Server

Calendar Server receiving timestamp request from clients

opentimestamps-server

Python

Common library

python-opentimestamps

Javascript

Common library & Client tool

javascript-opentimestamps

Java

Common library & Client tool

java-opentimestamps