Build and test regular expressions without leaving your browser
Type a pattern, paste sample text, and see matches highlighted live as you type — no need to run code in a separate environment just to check whether a regex behaves the way you expect.
Built-in pattern library
The sidebar includes ready-made patterns for common Indian formats: email addresses, 10-digit mobile numbers, URLs, PAN card numbers, PIN codes, dates and vehicle registration numbers — click one to load it instantly.
Reading the results
- Matches are highlighted directly in your test text.
- A match count and preview of the first few matches appear below.
- Invalid patterns show a clear error instead of silently failing.
Common use cases
Validating a form field's expected input format, extracting specific data (like phone numbers or dates) from a block of pasted text, checking a regex before pasting it into code, or simply learning regex syntax by experimenting with live feedback.
What do the flags field do?
Flags modify how the pattern matches — g finds all matches instead of just the first, and i makes the match case-insensitive. Both are enabled by default.
Does this support full JavaScript regex syntax?
Yes — patterns run through the browser's native RegExp engine, so anything valid in JavaScript regex works here, including lookaheads, character classes and groups.
Can I test capture groups?
Yes — patterns with parentheses for capture groups work normally, and matched groups are reflected in the match preview along with the full match.
Why does my pattern match more or less than I expect?
This is usually a flag issue — forgetting the g flag stops after the first match, while a missing i flag makes the match case-sensitive when you may have wanted otherwise.