Match Debugger
Related tools
Validators and utilities that complement Match Debugger — same session, no sign-up.
Flags:
Click "Debug" to run the regex and see match positions (start, end, length).
Debug regex matches: see start index, end index, length, and matched text for each match.
About this tool
Same inputs as Regex Tester (pattern, test string, flags). Results are shown in a debug table: start index, end index, length, matched text, and capture groups. Use this when you need character positions for debugging or tooling.
How to use this tool
- Paste your sample in the input (or fetch from URL if this tool supports it).
- Run the main action on the page to execute Match Debugger.
- Read the result, fix the source data or config, and re-run if needed.
What this check helps you catch
- Debug regex matches: see start index, end index, length, and matched text for each match.
- Limits called out in the description (what this tool does not verify — e.g. live network reachability, issuer databases, or strict schema contracts unless stated).
- Structural or syntax mistakes that would break parsers, serializers, or the next step in your workflow.
FAQ
- What does Match Debugger do?
- Debug regex matches: see start index, end index, length, and matched text for each match. Use the form above, then see “How to use” and “What this check helps you catch” for behavior detail.
- Is this a substitute for server-side validation?
- No. Use it for manual checks and triage; production systems should still validate and authorize on the server.
- Where does processing happen?
- Most validators here run in your browser. If a tool calls an API, that is stated on the page. See the site privacy policy for data handling.