Test JavaScript regex patterns with execution limits

How to use the workspace

1. Enter a JavaScript regex pattern without surrounding slash delimiters.
2. Choose flags and paste test input. Set the maximum match count if you need fewer results.
3. Run and inspect match positions, numbered captures and named groups. A deadline failure is a real failure, not a claim that nothing matched.

A concrete starting point

Pattern: (?<service>[a-z]+)-(\d+)
Flags: g
Input: edge-12 api-34
Named capture: service

Indices follow JavaScript string semantics. A zero-width match may have empty text and still be a valid match.

Read the result carefully

The supported flags are d, g, i, m, s, u, v and y where the browser supports them. Flags must be unique; u and v cannot be combined. The engine marks match-count truncation explicitly.

Common mistakes to avoid

• Nested backtracking patterns can consume the deadline with surprisingly short input.
• JavaScript regex syntax may differ from server-side regex dialects.
• This release inspects matches only. A replacement operation is not present in the frozen execution contract.

Limits & privacy

8 KiB pattern, 200 KiB input, up to 1,000 matches and a 1-second worker deadline. Cancel terminates the worker; no remote execution.