Sails.js, Koa.js, and Express.js - which Node.js framework should you use?

2017-05-17 14:52:39 Olga Node.js Interests 0 Comments

JavaScript is the fastest developing language today in IT, it has stopped being just a frontend language and has victoriously entered the backend world as well. As a runtime environment, Node.JS acts as backend JavaScript, giving the opportunity to create a high-load yet lightweight backend part for mobile app development. If you are still wondering which Node.JS framework to choose, keep on reading! We have chosen 3 of them for deeper analysis: Sails.js, Koa.js, and Express.js.

These 3 are MVC server frameworks which make them cross-browser and compatible with all operational systems and devices. So what are the differences? Let’s have a look. But first,  let us explain some technical details for better clarity.

How does an MVC framework function?

As the abbreviation says, the Model View Controller method is established on these 3 components:

  • Model - the database and business logic of your app.
  • View  - which is your application UI.
  • Controller - sends requests and updates info between the Model and View.

MVC frameworks are enterprise-grade solutions mostly because they allow operating big data, but they are not really flexible compared to a middleware frameworks, which requires less code to maintain apps.

How does a middleware framework function?

A middleware is a unit of software which knits up an operating system, a server and database and controls the information flows between the app and the three. 
For a Node.js app two types of a middleware can be created:

#1 Intermediary - a unit that processes requests and responses but is not empowered to control the requests. 

#2 End element - is a unit which is liable to control the final response. But bear in mind that an option to delegate to the next level is really useful for your app flexibility, in case you will want to add a layer in the future.

Why do we need both elements? If we speak about managing users, the intermediary allows to authenticate users and the end element is responsible for creating the users and showing their lists. Reasonably built middleware makes an app fast and scalable and reduces hanging.

And now let’s discuss the frameworks themselves.

1 Express.js

Express.js is a minimalistic Node framework for web apps with a wide range of functionality to create one or multiple page products and hybrid applications as well. The framework provides an opportunity for just-in-time activation and fast work, which positively affects the mobile app cost and quality.


Powerful API
With Express.js you can make a simple web app and extend it by means of route parameters and query strings. 

Huge diversity of plugins
Express.js provides an opportunity to distribute and install a huge quantity of third-party plugins which assist in solving any issue a developer can imagine.

Highly developed community
Being one of the most popular, Express.js is a very stable framework with an immense supportive community.


As to our mind, there are some serious disadvantages, which are pretty crucial, especially for less  experienced developers. 

No recommendations on how to organize a project
Express.js is a minimalistic and flexible framework which doesn’t give any tips on how to organize things. This can become confusing for beginners and cause a mess in their product’s structure.

Requires manual labour-intensive tasks
These is definitely not time-saving and can clutter the memory of your app.

What is Express.js good for?

For medium and lightweight projects, like PayPal and MySpace. If you have a complicated and massive project, it’s better to choose something different.

2 Koa.js

The inventors of this middleware framework claim that it’s a next generation item among frameworks for Node.js. Let’s see why it can be special. 


Argument #1 is that it’s just pleasant to realize the framework is developed by a team of professionals who also gave the IT world Express.js. Its philosophy is to create readable and concise code.

Robust and Lightweight like a feather

Basically, it’s just a code module which consists of only  550 lines of code!

Initial generator support 

The ES6 Generator feature allows avoiding the callbacks which makes the code clean, manageable and prevents bugs.

What is Koa good for?

With this modular framework, you can create a totally empty application which can be filled in with anything you need for a particular project.

3 Sails.js

This framework is based on the MVC pattern and provides you with all opportunities to create robust and neat applications. 


  • Sails ORM called Waterline makes the framework compatible with any kind of database.
  • Available backend templates which don’t require writing code.
  • Compatible with all front-end including custom hardware.
  • Thank Sails, all incoming socket messages are compatible with all routes in your app.
  • Skillful support.

What is Sails good for?

It’s a superb framework to create high-loaded enterprise products, real-time games, chat-rooms and similar. If your developers have had some experience with Express, everything should be smooth.

How to choose the framework you need?

First of all, you should define your goals and tasks, because there are dozens of good framework which can help you solve certain issues if you define them right. Having done that, take the following criteria into account:

  • Immense community
  • Regular version upgrade
  • Extensive documentation
  • Usage simplicity
  • High performance
  • Diversity of moduls
  • Customization

After studying some frameworks according to this points you will surely find at least one which is consistent with your needs.

Hopefully, this article helped you with choosing a Node.js framework.

At Cleveroad, we have experienced teams in all kinds of app development. If you have any ideas or questions, we are always glad to help you!

About the author
Olga Anoshyna is a Marketing Copywriter at Cleveroad, a web and app development company in Ukraine that successfully implements various projects of any complexity. The main goal of the company is to provide clients with quality and exceptional software.

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