A library, or module, is pre-written code that abstracts commonly required tasks. You can use libraries to speed up the coding process and promote the reusability of code, helping to keep your work “DRY” (don’t repeat yourself).
Axios is a promise-based HTTP client for browsers and Node.js. It also handles the transformation of request and response data from the browser or Node.js as needed.
Multer is a middleware library for Node.js. It’s written on top of the HTML form parser busboy and handles multipart and multiform data.
For example, if you are working with MongoDB predominantly, using Mongoose can be a lifesaver. CORS can help you deliver content from multiple domains, and Dotenv can be extremely handy if you need to share code — but not secrets — within a team.
Async is a powerful Node.js utility module that helps developers work with asynchronous JavaScript by working with JavaScript “async” or callback-accepting functions. If you pass an array of callbacks to the Async module, it executes and wraps them to return a promise.
The Async logo.
Features and Benefits of the Async Library
Provides some 70 utility functions to develop asynchronous control flow with ease
Offers “parallel” function for tackling multiple requests to a host (which would otherwise take a lot of code to implement)
Helps to eliminate nested “callback Hell” in JavaScript
6. Winston
Using JavaScript objects, Sequelize models the structure of database tables and connects to the desired relational database to query and transform data. It then parses and returns the retrieved data as a JavaScript object.
The Sequelize logo.
Features and Benefits of the Sequelize Library
Connects to databases and performs operations without writing raw SQL queries
Reduces SQL injection vulnerabilities and SQL injection attacks
Compatible with GraphQL
2. CORS
Now that you’ve had a peek at some of the most essential packages in Node.js, it’s time to build your own Node.js application. Kinsta’s Application Hosting and Database Hosting platforms can fast-track your development process. And you can get started for free on Kinsta’s Hobby Tier, scaling up when your application takes the world by storm.
Passport is a modular authentication middleware for Node.js. Passport features over 500 authentication strategies, including Google, Facebook, Twitter, and other custom and single sign-on (SSO) providers. Strategies include normal username and password authentication, delegated authentication using OAuth for social media sites, and OpenID for federated authentication.
The Passport logo.
Features and Benefits of the Passport Library
Built-in SSO authentication for social media sites with minimal code
Configures persistent login information across multiple sessions
Avoids mounting new routes in the application by using an unobstructed configuration with Express and Connect middleware
5. Async
Libraries in Node.js are managed using the Node.js package manager, npm, which can help install many open-source libraries. We’ve identified 13 essential libraries for Node.js that make a web developer’s life easier.
What Is Node.js?
Axios is isomorphic, meaning it can run on the server and the client with the same codebase. For HTTP communication, Axios uses a native HTTP module on the server side and XMLHttpRequest on the client side.
The Axios logo.
Features and Benefits of the Axios Library
Offers built-in API functions for common HTTP data types like GET, PUT, POST, and DELETE
Provides more security through cross-site request forgery (CSRF) protection while making HTTP requests across the Internet
Easily transforms response data to JSON through automatic JSON data transformation
11. Puppeteer
Mongoose is a Node.js based object modeling tool for MongoDB, also known as an object data modeling (ODM) library, which offers a variety of functions like hooks, model validation, connecting, and querying.
The CORS package forms a wrapper around the Node.js route middleware, enabling the application to access resources from domains other than its own. It takes in multiple parameters to configure cross-origin options, including origin, headers, and more.
An example of CORS code (configuration).
Features and Benefits of the CORS Library
Reduces the amount of code required to enable CORS in a web application
Allows you to configure allow-listed domains and lets the user enable CORS for selected origins while blocking others
Provides seamless error handling and helps developers analyze security threats from suspicious origins
3. Nodemailer
CORS is a Node.js package for providing cross-origin resource sharing (CORS) as middleware that draws on Connect/Express.
Mongoose provides a schema-based solution for application data by enforcing a single schema at the application layer that makes a collection in MongoDB. Each schema is associated with a Mongoose model, which allows you to run queries against a MongoDB collection, like fetching, updating, and deleting data.
The Mongoose logo.
Features and Benefits of the Mongoose Library
Provides easy abstraction of queries, allowing developers to write less code for MongoDB transactions
Built-in data validation for defining rules on what kind of data can be added or updated in the database
Implements a predefined structure for the MongoDB collection, which provides a boiler-plate MongoDB instance for developers
Allows query chaining for working with multiple queries
8. Socket.IO
Node.js supports code reusability through JavaScript libraries, but choosing the best libraries can be daunting. Useful libraries can accelerate development time and have a wide range of benefits for your web application, including faster load times and reduced application bundle size.
Node.js has become the go-to runtime environment for many developers working on web applications. Built to run code written in JavaScript, one of the most popular programming languages in the world, Node.js makes the building of server-side applications accessible to a large community of developers.
After initializing the Multer instance, it takes in a dest object as one of its options to specify where the uploaded file will be stored on the server. Multer sends a file object along with the upload request, which is then parsed and sent to the destination location by Multer API.
An example of Multer code with HTML form markup.
Features and Benefits of the Multer Library
Makes raw HTTP request data more accessible for storage through built-in parsing
Lets you specify the encoding type for the file, which adds an additional layer of security to the uploaded file
Filters and can limit upload options for file type and size
13. Dotenv
Aside from the default, the createLogger function helps you create custom loggers that use available transport options such as consoles, files, and databases. Custom loggers can also be used with custom transports.
An example of Winston code.
Features and Benefits of the Winston Library
Centralizes control over logging through a single config file
Allows for customizable log formats, as when storing your log in a JSON format or as text
Provides customizable logging levels which you can configure according to your application needs
7. Mongoose
Node.js uses an event-driven and non-blocking I/O, which makes it highly efficient in real-time distributed applications that deal with a lot of data.
What Is a Node.js Library?
It uses Engine.IO to establish a low-level connection between the server and the client, using a digital handshake through HTTP long-polling. Once it establishes the connection, the client and server communication occurs in real-time over TCP.
The Sockets.IO logo.
Features and Benefits of the Sockets.IO Library
Provides a low-overhead communication channel using WebSocket and allows HTTP long-polling as a fallback option
Scalable and allows servers to broadcast events to multiple clients easily
Supports multiplexing through namespaces, which minimizes the number of TCP connections used and reduces socket ports on the server