Regex for URL Validation — Pattern Explained with Examples

URL validation is essential wherever users input web addresses — social media profiles, link sharing, website fields, and CMS systems. This pattern checks for the standard URL structure including protocol, domain, optional path, query parameters, and fragment identifiers.

The Pattern

/^https?:\/\/([\w-]+\.)+[\w-]+(\/[\w\-./?%&=]*)?$/

Pattern Breakdown

Matches

• https://example.com
• http://sub.domain.com/path?q=1
• https://example.com/page#section
• http://example.io
• https://api.example.org/v1/users?id=5&page=2

Does NOT Match

• example.com (missing protocol)
• http:///path (missing domain)
• ftp://server (wrong protocol prefix)
• https:// example.com (space in URL)
• http://.com (no domain name)
• https://exa_mple.com/invalid space (space in path)

Language Examples

JavaScript

const urlRegex = /^https?:\/\/([\w-]+\.)+[\w-]+(\/[\w\-./?%&=]*)?$/;
console.log(urlRegex.test('https://example.com'));          // true
console.log(urlRegex.test('example.com'));                   // false

Python

import re
pattern = r'^https?:\/\/([\w-]+\.)+[\w-]+(\/[\w\-./?%&=]*)?$'
print(bool(re.match(pattern, 'https://example.com')))   # True
print(bool(re.match(pattern, 'example.com')))            # False

Java

import java.util.regex.Pattern;

public class UrlValidator {
    private static final Pattern URL_PATTERN =
        Pattern.compile("^https?://([\\w-]+\\.)+[\\w-]+(/[\\w\\-./?%&=]*)?$");

    public static boolean isValid(String url) {
        return URL_PATTERN.matcher(url).matches();
    }
}

Common Pitfalls

• No single regex covers every valid URL format — edge cases like authentication (user:pass@host), IPv6 literal hosts, and data URIs all need different patterns
• Protocol-relative URLs (//example.com) are valid in web contexts but will be rejected by a pattern requiring http:// or https://
• Internationalized domain names (IDN) use non-ASCII characters that standard \w does not match
• Deep query strings with special characters like +, &, and = may fail depending on the escape handling

Real-World Use Cases

• Link submission forms — validate user-submitted URLs before storing in a database or sharing on a platform
• SEO tools — check that sitemap entries and backlink lists contain properly formatted URLs
• API request validation — ensure incoming webhook URLs or callback parameters are well-formed before making outbound requests

FAQ

Related Patterns

Regex for Email Regex for IPv4 Address