The clean, readable, proven library for Bitcoin JavaScript development.

A pure JavaScript Bitcoin library for node.js and browsers. Used in production by over 1.5 million wallet users, BitcoinJS is the backbone for almost all Bitcoin web wallets in production today.

BitcoinJS 1.0 has been released! Click here to read the announcement.


Who's using BitcoinJS

* directly contributed code or funding to the project.

Who's not

Get Started

Install via NPM

$ npm install -g bitcoinjs-lib

Compile for browser

$ npm -g install bitcoinjs-lib browserify uglify-js
$ browserify -r bitcoinjs-lib -s Bitcoin | uglifyjs > bitcoinjs.min.js


Generating a Bitcoin address:

key = bitcoin.ECKey.makeRandom()

// Print your private key (in WIF format)
// => Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct

// Print your public key (toString defaults to a Bitcoin address)
// => 14bZ7YWde4KdRb5YN7GYkToz3EHVCvRxkF

Creating a Transaction

tx = new bitcoin.Transaction()

// Add the input (who is paying) of the form [previous transaction hash, index of the output to use]
tx.addInput("aa94ab02c182214f090e99a0d57021caffd0f195a81c24602b1028b130b63e31", 0)

// Add the output (who to pay to) of the form [payee's address, amount in satoshis]
tx.addOutput("1Gokm82v6DmtwKEB8AiVhm82hyFSsEvBDK", 15000)

// Initialize a private key using WIF
key = bitcoin.ECKey.fromWIF("L1uyy5qTuGrVXrmrsvHWHgVzW9kKdrp27wBC7Vs6nZDTF2BRUVwy")

// Sign the first input with the new key
tx.sign(0, key)

// Print transaction serialized as hex
// => 0100000001313eb630b128102b60241ca895f1d0ffca21 ...

// You could now push the transaction onto the Bitcoin network manually (see


Soon. For now, use the tests as a reference. They show what the code is supposed to do.


Stefan Thomas is the inventor and creator of this project. His pioneering work made Bitcoin web wallets possible.

Since then, many developers have joined in to improve the library. Click here to see the full list.

Daniel Cousens, Wei Lu, JP Richardson and Kyle Drake lead the major refactor of the library from 0.1.3 to 1.0.0.


We always welcome help on the library. If you want to help build (or fix bugs), fork the repository, create a topic branch (keep it focused, and ADD TESTS), make the change, commit to your forked repo, and send a pull request.

Trustless, or Bust.

Fork me on GitHub