How to Use Regex Tester

The Regex Tester provides instant visual feedback as you build patterns. Enter your regular expression in the pattern field — matches highlight in the test string in real-time. Use flags like /g (global), /i (case-insensitive), and /m (multiline) by toggling the flag buttons. The matched groups panel shows all capture groups with their values and positions. Switch to the replacement tab to test substitution patterns. The built-in cheatsheet provides quick reference for regex syntax. Common patterns like email, URL, and phone number validation are available as templates. Copy your tested regex with one click.

Frequently Asked Questions

What regex flavors are supported?

The tool primarily supports JavaScript regex syntax. It covers most common patterns including groups, lookahead, and character classes.

Does it show capture groups?

Yes, all capture groups are displayed with their matched content, index positions, and group names (for named groups).

Can I test replacement patterns?

Yes, enter a replacement string and see the result of applying your regex replacement to the test text in real-time.

Is there a regex cheatsheet?

Yes, the tool includes a built-in reference panel with common patterns, quantifiers, character classes, and special tokens.

Can I share my regex test?

Copy the regex pattern and test string to share, or use the shareable URL that encodes your pattern and test data.