A Node.js and browserify leveldown API implementation that maps to localstorage in the browser


Localstorage implementation of leveldown for mobile and desktop browsers.

The idea is to be able to use the level stack on phone and desktops.

The scenarios envisaged are :

  1. Occasionally connected clients

  2. Adhoc Networks where clients need to sync directly with each other.

This project is intended for use with the level eco-system.

npm install localstorage-down

Basically we support any browser that has localStorage, but since we also rely on an ES5 environment due to dependencies from abstract-leveldown, in practice you will need the following shims in order to work correctly on all browsers (e.g. IE 8/9):

At the command prompt in your chosen directory :

npm install localstorage-down
npm install levelup 
npm install browserify -g
npm install beefy -g

Create a file called index.js and enter the following:

var localstorage = require('localstorage-down');
var levelup = require('levelup');
var db = levelup('/does/not/matter', { db: localstorage });
db.put('name', 'Yuri Irsenovich Kim');
db.put('dob', '16 February 1941');
db.put('spouse', 'Kim Young-sook');
db.put('occupation', 'Clown');
   .on('data', function (data) {
      if (typeof data.value !== 'undefined') {
         console.log(data.key, '=', data.value);
   .on('error', function (err) {
      console.log('Oh my!', err);
   .on('close', function () {
      console.log('Stream closed');
   .on('end', function () {
     console.log('Stream ended');

Publish the site :

beefy index.js

See the output :


Listen to John Cage :


npm run test

Browse to http://localhost:9966. View console logs in the browser to see test output.

Anton Whalley https://github.com/no9

Adam Shih https://github.com/adamshih

Nolan Lawson https://github.com/nolanlawson