How to use it
Use this tester when a JavaScript regular expression needs repeatable match, group, index, or replacement checks.
- Enter a pattern without slash delimiters and select only the flags you need.
- Paste test text and optionally enter an ECMAScript replacement string.
- Run the test, then review match indices, capture groups, and the replacement preview.
Worked example
- Input
Pattern: (?<word>[A-Za-z]+)-(\d+)
Text: Rigula-12
- Output
Match 1: Rigula-12 · word=Rigula · group 2=12
Named and numbered groups are shown as data, never executed as markup.
Method and definitions
- The page uses the current browser's ECMA-262 RegExp implementation and always scans globally.
- Evaluation runs in a worker with a two-second deadline; zero-length Unicode matches advance safely.
Limits and edge cases
- This is not a PCRE, RE2, Java, .NET, or Python compatibility tester.
- Pattern, text, time, and displayed-match limits prevent a page from becoming an unbounded regex workload.
Privacy
All input and output stays in this tab. Rigula does not upload, store, or include it in a share URL.
Sources
