20 Regex Patterns Every Developer Needs: Copy-Paste Ready Examples

Stop writing regex patterns from scratch. Here are 20 battle-tested patterns that cover the most common validation and extraction needs. Each pattern includes an explanation and example matches.

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Validation Patterns

1. Email Address

^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$

Matches: user@example.com, john.doe+tag@company.co.uk

Does not match: user@, @example.com, user@.com

2. URL (HTTP/HTTPS)

^https?:\/\/(www\.)?[-a-zA-Z0-9@:%._+~#=]{1,256}\.[a-zA-Z0-9()]{1,6}\b([-a-zA-Z0-9()@:%_+.~#?&/=]*)$

Matches: https://example.com, http://www.site.co.uk/path?q=1

3. Phone Number (International E.164)

^\+[1-9]\d{1,14}$

Matches: +14155552671, +442071234567

Use this for international phone numbers. For US-specific, see pattern #4.

4. US Phone Number

^(\+1)?[\s.-]?\(?\d{3}\)?[\s.-]?\d{3}[\s.-]?\d{4}$

Matches: (415) 555-2671, 415-555-2671, +1 415.555.2671

5. Strong Password

^(?=.*[a-z])(?=.*[A-Z])(?=.*\d)(?=.*[@$!%*?&])[A-Za-z\d@$!%*?&]{8,}$

Requires: 8+ characters, uppercase, lowercase, digit, and special character.

Matches: MyP@ss1word | Does not match: password, 12345678

6. IPv4 Address

^((25[0-5]|(2[0-4]|1\d|[1-9]|)\d)\.?\b){4}$

Matches: 192.168.1.1, 10.0.0.255

Does not match: 256.1.1.1, 192.168.1

7. IPv6 Address (Simplified)

^([0-9a-fA-F]{1,4}:){7}[0-9a-fA-F]{1,4}$

Matches full IPv6 addresses like 2001:0db8:85a3:0000:0000:8a2e:0370:7334

8. Date (YYYY-MM-DD)

^\d{4}-(0[1-9]|1[0-2])-(0[1-9]|[12]\d|3[01])$

Matches: 2026-01-15, 2025-12-31

Does not match: 2026-13-01, 2026-00-15

Extraction Patterns

9. Extract All Emails from Text

[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

Use with global flag (g) to find all email addresses in a block of text.

10. Extract All URLs from Text

https?:\/\/[^\s<>\"']+

A simpler, more forgiving URL pattern for extraction (not strict validation).

11. Extract HTML Tags

<([a-zA-Z][a-zA-Z0-9]*)\b[^>]*>(.*?)<\/\1>

Captures tag name and content. Use \1 backreference for matching close tags.

Warning: For complex HTML parsing, use a proper parser like DOMParser or cheerio.

12. Extract Numbers from String

-?\d+\.?\d*

Matches: integers and decimals, positive and negative. 42, -3.14, 0.5

13. Extract Hashtags

#[a-zA-Z0-9_]+

Matches: #javascript, #dev_tools, #React18

Format Patterns

14. Credit Card Number (Basic)

^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|3[47][0-9]{13}|6(?:011|5[0-9]{2})[0-9]{12})$

Matches: Visa, Mastercard, Amex, Discover.

For production, use a payment processor's validation — never validate cards with regex alone.

15. Hex Color Code

^#([0-9A-Fa-f]{3}|[0-9A-Fa-f]{6}|[0-9A-Fa-f]{8})$

Matches: #FFF, #FF5733, #FF573380

16. Semantic Version (SemVer)

^(0|[1-9]\d*)\.(0|[1-9]\d*)\.(0|[1-9]\d*)(?:-((?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*)(?:\.(?:0|[1-9]\d*|\d*[a-zA-Z-][0-9a-zA-Z-]*))*))?(?:\+([0-9a-zA-Z-]+(?:\.[0-9a-zA-Z-]+)*))?$

Matches: 1.0.0, 2.1.3-beta.1, 1.0.0+build.123

17. UUID (Any Version)

^[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$

Matches: f47ac10b-58cc-4372-a567-0e02b2c3d479

Text Processing Patterns

18. Trim Whitespace (Leading + Trailing)

^\s+|\s+$

Use with replace to trim: text.replace(/^\\s+|\\s+$/g, '')

19. Multiple Spaces to Single Space

\s{2,}

Replace with single space: text.replace(/\\s{2,}/g, ' ')

20. Markdown Bold Text

\*\*(.+?)\*\*

Captures text between ** markers. Group 1 contains the bold text.

Using These Patterns in Code

// JavaScript
const emailRegex = /^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$/;
emailRegex.test('user@example.com'); // true

// Python
import re
pattern = r'^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}$'
re.match(pattern, 'user@example.com')  # Match object

// Java
Pattern pattern = Pattern.compile("^[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}$");
pattern.matcher("user@example.com").matches(); // true

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