Developer

Regex Tester

Write a pattern and see matches highlighted as a list, with capture groups, positions and an optional replace preview.

Developer

Regular expression tester

Local only

PatternTest stringReplacement (optional — use $1 for groups)

2matches with /\b[a-z]+@[a-z]+\.[a-z]{2,}\b/gi

#	Match	Index	Groups
1	`hello@tooltouse.com`	9	—
2	`support@example.org`	32	—

Your pattern and text never leave your browser

Matching uses the browser's own regular expression engine on your device.

Testing regular expressions

The tester runs your pattern against the test string as you type and lists every match with its starting index and capture groups, so you can confirm a pattern before putting it into code.

Flags

g — find all matches rather than stopping at the first.
i — ignore letter case.
m — make ^ and $ match at each line break.
s — let the dot match newlines.
u — treat the pattern as Unicode.

Good to know

Frequently asked questions

Which regex flavour is used?

JavaScript's own RegExp engine, so patterns behave exactly as they will in browser or Node code.

Is my test data uploaded?

No. Matching happens entirely on your device.

How do I use capture groups in the replacement?

Use $1, $2 and so on, matching the order of the groups in your pattern.

Why does it show fewer matches than expected?

The list stops at 500 matches to keep the page fast. Narrow the test string to see the rest.

Regular expression tester

Testing regular expressions

Flags

Frequently asked questions

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