Which regex engine is used?

The shared Regex Tester ECMAScript parser and a timeout-protected Worker are used. PCRE-only constructs are diagnosed rather than translated.

/text local tool

Suggest an improvement

Regex Visualizer

Inspect a pattern token by token, including named groups and match spans.

Local execution receiptinput path disclosedTool content stays out of MonoTools URLs and API requests.

Working input: Browser memory
Cross-tool handoff: Session only · 10 min
URL payload: Never
Export: Explicit action

Verify it: open DevTools Network, clear the log, use the tool, then inspect fetch/XHR requests. Page assets and optional aggregate analytics may use the network; tool input is not included.

Full privacy model

Loading tool...

How to use

01Enter a regex pattern and flags.
02Paste representative sample text.
03Review token explanations and copy the match report.

FAQ

Which regex engine is used?: The shared Regex Tester ECMAScript parser and a timeout-protected Worker are used. PCRE-only constructs are diagnosed rather than translated.

Related tools

→
/textJavaScript Regex TesterExplain, test and regression-check JavaScript regex safely.
→
/textText DiffDiff text by line, word or character and apply patches.
→
/textLogfmt / NDJSON InspectorRecover, filter and redact mixed logfmt or NDJSON lines.
→
/webMagic PasteDetect pasted developer data and open the right tool.