ESLint is a programming tool (Linter) that checks the correctness and appearance of Javascript code according to established rules. It is very useful when working in a larger group of people, because each programmer has his own coding style. Thanks to ESLint, we can minimize differences in style and also prevent possible errors from the editor level. Apart from ESLint, we can use other liners like StyleLint for CSS, or linter for PHP.

ESLint Homepage