20 Common Regex Patterns Every Developer Should Know

Essential Regex Patterns

Here are 20 regex patterns you'll use regularly in your development work.

Validation Patterns

1. Email Address

``

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

`

2. URL

`

https?:\/\/[\w\-._~:/?#[\]@!$&'()*+,;=%]+

`

3. Phone Number (US)

`

\(?\d{3}\)?[-.\s]?\d{3}[-.\s]?\d{4}

`

Matches: (555) 123-4567, 555-123-4567, 555.123.4567

4. IPv4 Address

`

\b(?:\d{1,3}\.){3}\d{1,3}\b

`

5. Date (YYYY-MM-DD)

`

\d{4}-\d{2}-\d{2}

`

6. Time (HH:MM)

`

([01]?\d|2[0-3]):[0-5]\d

`

7. Hex Color

`

#[0-9A-Fa-f]{6}\b

`

8. Credit Card (Basic)

`

\d{4}[- ]?\d{4}[- ]?\d{4}[- ]?\d{4}

`

9. ZIP Code (US)

`

\d{5}(-\d{4})?

`

10. Username

`

^[a-zA-Z0-9_]{3,16}$

`

Extraction Patterns

11. Extract Domain from URL

`

https?:\/\/([^/]+)

`

Group 1 captures the domain

12. Extract Hashtags

`

#(\w+)

`

13. Extract Mentions

`

@(\w+)

`

14. Extract Numbers

`

-?\d+\.?\d*

`

15. Extract HTML Tags

`

<([a-z]+)[^>]*>

`

Text Processing

16. Remove Extra Whitespace

`

\s+

`

Replace with single space

17. Match Words Only

`

\b\w+\b

`

18. Match Quoted Strings

`

"([^"]*)"

`

19. Match Parenthetical Content

`

\(([^)]+)\)

`

20. Split by Multiple Delimiters

`

[,;\s]+

``

Usage Tips

Always test patterns with edge cases

Consider using non-capturing groups (?:) when you don't need the capture

Anchor patterns (^ $) when validating entire strings

Use RegexSpark to test and debug your patterns in real-time