Validate a url using regex in Javascript

If you want to check if a URL string is valid or not, you can use regular expressions in Javascript. You can test any string against that regex and it will return true if the URL is valid.

function validate_url(url) {
    const url_regex = /^(?:(?:(?:https?|ftp):)?\/\/)(?:\S+(?::\S*)?@)?(?:(?!(?:10|127)(?:\.\d{1,3}){3})(?!(?:169\.254|192\.168)(?:\.\d{1,3}){2})(?!172\.(?:1[6-9]|2\d|3[0-1])(?:\.\d{1,3}){2})(?:[1-9]\d?|1\d\d|2[01]\d|22[0-3])(?:\.(?:1?\d{1,2}|2[0-4]\d|25[0-5])){2}(?:\.(?:[1-9]\d?|1\d\d|2[0-4]\d|25[0-4]))|(?:(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)(?:\.(?:[a-z\u00a1-\uffff0-9]-*)*[a-z\u00a1-\uffff0-9]+)*(?:\.(?:[a-z\u00a1-\uffff]{2,})))(?::\d{2,5})?(?:[/?#]\S*)?$/i;

    return url_regex.test(url);
}

console.log( validate_url("invalidurl.com") );
// -> false

console.log( validate_url("http://validurl.com") );
// -> true

Output

false
true

Example 2: Another example of validating URL string using regex in javascript

function validate_url(url_str) {
    var regex = /^((https?):\/\/)?([w|W]{3}\.)+[a-zA-Z0-9\-\.]{3,}\.[a-zA-Z]{2,}(\.[a-zA-Z]{2,})?$/;

    return regex.test(url_str)
}

console.log( validate_url("domain.com") );

console.log(validate_url("http://www.domain.com"));

You will also have to use "www" in your URL string to validate it otherwise it will not be valid.

Was this helpful?