Regex Tester

Try a regex instantly

Regular expressions describe text patterns like “3 digits, dash, 3 digits, dash, 4 digits”. They're everywhere — code, data cleanup, spreadsheet REGEX functions, find-and-replace in editors — and one wrong character changes everything. This tool highlights matches as you type and lists positions and capture-group values in a table, so you can see at once whether the pattern does what you mean.

Flags

• g — find all matches, not just the first.
• i — ignore case.
• m — ^ and $ match at the start and end of each line.
• s — the dot (.) also matches line breaks.
• u — Unicode mode; needed for emoji and properties like \p{L}.

Replace and common patterns

Type a replacement to preview the result. $1, $2 refer to the first and second capture groups and $& to the whole match — for example, $1-***-$3 masks the middle of a phone number. Ready-made patterns for phone numbers, email, URLs, dates, ZIP codes, letters in any language, HTML tags and IP addresses can be tried from the list. They're meant for finding common formats, not for strict validation of every edge case.

This uses your browser's JavaScript regex engine. Most syntax matches Python, Java and spreadsheet regex, but some features (lookbehind, named-group syntax) can differ. Runaway patterns are stopped after 1 second so the page never hangs. Your text never leaves your device.