JAVASCRIPT
Validating URLs with Regular Expressions
Use this JavaScript regex pattern to accurately validate various URL formats, including HTTP/HTTPS protocols, domains, and optional paths, for robust input checks.
function isValidURL(url) {
const urlRegex = /^(https?:\/\/)?([a-zA-Z0-9-]+\.)+[a-zA-Z]{2,}(:\d{1,5})?(\/[^\s]*)?$/i;
return urlRegex.test(url);
}
// Example usage:
console.log(isValidURL("https://www.example.com/path/to/page?id=1")); // true
console.log(isValidURL("http://sub.domain.co.uk:8080")); // true
console.log(isValidURL("example.com")); // true (without protocol)
console.log(isValidURL("ftp://not-a-url.com")); // false
console.log(isValidURL("invalid url")); // false
How it works: This JavaScript function employs a regular expression to validate common URL structures. It supports both 'http://' and 'https://' protocols (making them optional), domain names with various TLDs, optional port numbers, and paths. The 'i' flag ensures the pattern is case-insensitive, making it more flexible for URL validation.