tools / text & data
regex tester
Live match highlighting, capture groups, and a common-pattern library.
/ /
flags
matches
enter a pattern and some text
result
common patterns
note: JavaScript's regex engine backtracks. A
pathological pattern (e.g. (a+)+$) on a long
non-matching string can stall this tab — the match/length caps limit match
count, not time inside a single attempt. There's no perfect ReDoS guard;
everything runs locally, so only your own tab is ever at risk.
examples