validateURL

1/**
2 * Validates whether a string is a well-formed URL.
3 *
4 * @param url - The string to validate.
5 * @returns True if the string is a valid URL, otherwise false.
6 */
7export function validateURL(url: string): boolean {
8  try {
9    new URL(url);
10    return true;
11  } catch {
12    return false;
13  }
14}

• Native API Usage

  Leverages the built-in URL constructor for accurate and standards-compliant validation without relying on regular expressions.

• Broad Format Support

  Correctly recognizes a wide range of valid URL schemes and structures (e.g., with/without protocols, ports, query parameters).

• Minimal Overhead

  Simple, fast, and lightweight — ideal for high-frequency validations with negligible performance impact.

• Robust Error Handling

  Reliably catches malformed input through try-catch, avoiding crashes or unhandled exceptions.

Tests | Examples

1test('validateURL - valid HTTP URL', () => {
2  expect(validateURL('http://example.com')).toBe(true);
3});
4
5test('validateURL - valid HTTPS URL', () => {
6  expect(validateURL('https://example.com')).toBe(true);
7});
8
9test('validateURL - valid URL with path and query', () => {
10  expect(validateURL('https://example.com/path?query=1')).toBe(true);
11});
12
13test('validateURL - invalid string', () => {
14  expect(validateURL('not a url')).toBe(false);
15});
16
17test('validateURL - missing protocol', () => {
18  expect(validateURL('example.com')).toBe(false);
19});
20
21test('validateURL - empty string', () => {
22  expect(validateURL('')).toBe(false);
23});

Common Use Cases

• Form Validation

  Ensure URLs entered by users (e.g., in contact forms, profile links) are properly structured.

• Content Moderation or Filtering

  Automatically detect and validate URLs in submitted text (e.g., comments, messages).

• Link Preview Generation

  Pre-check links before attempting to fetch metadata or embed previews.

• URL Whitelisting/Blacklisting

  Confirm valid structure before applying security rules or matching against a list.

• Sanity Checks Before Redirection or Fetch

  Prevent errors by validating URLs before using them in navigation or API calls.