The Most Critical JavaScript Security Rules Every Developer Must Follow

Supercharge your code security in 8 simple steps

Photo by Adi Goldstein on Unsplash

JavaScript powers most of the web — it brings sites to life, enables complex web apps, and provides utility that HTML and CSS simply can’t. But with great power comes great responsibility. JavaScript gives developers immense control over the user experience, and if you aren’t careful, that control can be abused or exploited by attackers.

Don’t let your JavaScript become a security liability. By following these 8 JavaScript security best practices, you can write code that works hard for you instead of against you.

1. Use a Linter Like ESLint

A good JavaScript linter like ESLint will catch an entire class of bugs by automatically scanning your code for issues on every save. The rules can check for improper syntax, prevent you from using deprecated functions, enforce consistent code style, and even catch logical coding gaffes. Set it up early in your project to prevent headaches down the road.

// ESLint example

var unlockedDoor = true; 

if(unlockedDoor = true) {
  // ESLint throws warning - using single = instead of ===
}

2. Validate and Sanitize All User Input