JavaScript - case insensitive string comparison

In this article, we would like to show you how to do case-insensitive string comparison in JavaScript.

Quick solution:

// ONLINE-RUNNER:browser;

var text1 = 'ABC';
var text2 = 'abc';

var result = text1.toUpperCase() === text2.toUpperCase();

console.log(result);  // true

Note:

You can also use toLowerCase() method instead of toUpperCase().

Practical example

In this example, we create a reusable function using modern JavaScript syntax for case-insensitive string comparison.

// ONLINE-RUNNER:browser;

const areEqual = (string1, string2) => {
    return string1.toUpperCase() === string2.toUpperCase();
};


// Usage example:

const text1 = 'ABC';
const text2 = 'abc';
const text3 = 'AbC';

console.log(areEqual(text1, text2));  // true
console.log(areEqual(text1, text3));  // true
console.log(areEqual(text2, text3));  // true