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Regex Tester

Test JavaScript regular expressions and flags against sample text in your browser.

Match results

[0] Hello
[1] World
[2] Regex
[3] Test

About Regex Tester

Regex Tester runs the supplied pattern and flags with the browser JavaScript RegExp engine.

Input is processed locally in your browser and is not sent to Navorika.

How to use this tool

  1. 1Enter a JavaScript regular expression and supported flags.
  2. 2Enter or paste the test text.
  3. 3Review each match or correct any reported syntax error.

Understanding the result

Results use JavaScript regular-expression semantics.

The numbered list shows the strings returned by String.match for the selected flags.

Important limitations

  • Pathological expressions can consume substantial CPU time.
  • It does not explain patterns, generate expressions, or emulate other regex engines.

Explore this topic

Frequently asked questions

Which regex flavor is used?

The browser JavaScript RegExp implementation.

Does it show syntax errors?

Yes, invalid patterns or flags display the browser error.

Is test text uploaded?

No.

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