Developer Tools
Regex Tester - See Pattern Matches in Real Time
Type a regex pattern and a test string to see matches highlighted in real time. Toggle flags and inspect capture groups.
Matches
Why regex needs live testing
Regular expressions are the most powerful tool for finding strings that follow a specific rule, whether that is an email, a phone number, or a date format. But tweaking one part of a pattern often tangles another, so it is hard to refine without seeing the result against real input. This tool puts the pattern and test string side by side and highlights every match.
The g, i, m, and s flags toggle with a checkbox, and along with the match count it lists the position and content of each match plus the capture groups, so even complex patterns read at a glance. Syntax errors show up the moment they happen, which makes it quick to narrow down the cause. Everything runs locally in your browser.
Who gets the most out of it
- Backend and frontend developers — refining input-validation patterns
- Data analysts and engineers — pulling patterns out of logs and text
- QA engineers — locating specific formats inside test data
- Anyone learning regex — seeing exactly how a pattern matches
Flags at a glance
- g — global matching. Does not stop at the first match; finds them all.
- i — case-insensitive matching.
- m — ^ and $ match the start and end of each line.
- s — . matches newline characters as well.
Frequently asked questions
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