local-only

Regex Tester

Test regular expressions live with match highlighting.

🔒 local memory only
Initializing Regex Tester in local browser environment…

How to use Regex Tester

  1. Type or paste your regular expression pattern in the pattern input box.
  2. Toggle regex flags: global (g), case-insensitive (i), multiline (m), or dotall (s).
  3. Input your test string in the text editor below.
  4. Inspect matches highlighted in real time along with full capture group extractions.

Why use this local-first tool?

  • Real-time syntax verification using the browser native RegExp engine.
  • Visual inline highlighting with capture group index and naming breakdown.
  • Preset patterns for emails, URLs, dates, hex colors, and IPv4 addresses.
  • Zero server latency and full confidentiality for proprietary log formats or regex security patterns.

Frequently Asked Questions

Which regular expression flavor does this tester use?

It uses standard ECMAScript (JavaScript) RegExp as implemented by your web browser, supporting Unicode property escapes, lookarounds, and named capture groups.

Are my proprietary logs or test strings recorded or logged?

Never. The RegExp execution is completely confined to your browser tab.

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