D01
Regex tester
Live matches and capture groups, run in a Worker with a timeout so backtracking cannot hang the page.
WHAT IT WILL NOT DO
- The scan stops at 1000 matches; the rest of the text is never examined, so paste long files in sections.
- Positions are UTF-16 code-unit offsets, not character counts.
- It runs the browser JavaScript engine: no PCRE recursion, no RE2 linear-time guarantee.