Regex TesterTest JavaScript regular expressions against sample text, right in your browser.

Yes. Matching happens entirely in your browser — nothing is sent to BroBroGo.

g finds every match instead of just the first. i ignores case. m makes ^ and $ match the start and end of each line instead of just the whole string. s lets . also match line breaks.

Some patterns trigger catastrophic backtracking — the engine tries an exponential number of combinations before giving up, which can freeze a browser tab. This tool runs matching in a background worker and cancels it after 2 seconds if that happens, so the page itself never locks up. Try simplifying nested repetition like (a+)+.