NeDB: a lightweight Javascript database using MongoDB's API



This is a guest post by Louis Chatriot

Sometimes you need database functionality but want to avoid the constraints that come with installing a full-blown solution. Maybe you are writing a Node service or web application that needs to be easily packageable, such as a continuous integration server. Maybe you’re writing a desktop application with Node Webkit, and don’t want to ask your users to install an external database. That’s when you need NeDB.

NeDB is a lightweight database written entirely in Javascript, and that implements the well-known and loved MongoDB API. It is packaged as a Node module that be used with a simple require and can be used as an in-memory only or persistent datastore. You can think of it as SQLite for MongoDB projects.

var Nedb = require('nedb')
  , planets = new Nedb({ filename: 'path/to/data.db', autoload: true });
// Let's insert some data
planets.insert({ name: 'Earth', satellites: 1 }, function (err) {
  planets.insert({ name: 'Mars', satellites: 2 }, function (err) {
    planets.insert({ name: 'Jupiter', satellites: 67 }, function (err) {
      // Now we can query it the usual way
      planets.find({ satellites: { $lt: 10 } }, function (err, docs) {
        // docs is an array containing Earth and Mars


NeDB implements the most widely used features of MongoDB:

  • CRUD operations including upserts
  • Ability to persist data
  • Expressive query language where you can use dot notation (to query on nested documents), regular expressions, comparison operators ($lt, $lte, $gt, $gte, $in, $nin, $exists) and logical operators ($and, $or, $not)
  • Documents modifiers $set, $inc, $push, $pop, $addToSet and $each
  • A browser version


Of course, NeDB is not a replacement for a “real” database such as MongoDB, so its goal is not to be as fast as possible, it is to be fast enough. And it is: using indexing, it achieves about 5,000 writes and 25,000 reads per second. If you need more than this, you’re probably not writing a small application!

Want to try it?

You can npm install it, the module name is nedb. You can also check the Github repository to read the documentation, give feedback, raise issues or send pull requests