#regex

A client-side regex find-and-replace tool: enter a pattern, toggle flags, write a replacement with $1 / $<name> capture references, and watch the transformed text update live.

Look up regex syntax fast: character classes, anchors, quantifiers, groups, lookaround, flags, and ready-made patterns for email, URL, IPv4, dates and more.

Break any regex pattern into plain-English token cards, see a railroad diagram, lint risky patterns, and translate across regex flavors.