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Regex test

Test and debug regular expressions

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Regex test

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Contact email: hello@example.com, backup email: support@usefulshelf.com
Contact email: [hello@example.com], backup email: [support@usefulshelf.com]
Instructions

Write regex with live match results

Use for validating rules, filtering text, or debugging expressions.

1Enter regex pattern
2Paste test text
3View match and replacement results
After completionVerify the regex matches the expected content.Enter Regex and Test Text First

Test a regex with both matches and non-matches

This tester uses browser JavaScript regular expressions. One successful match only validates that sample, not every possible input.

An example to check

Input and settings

/[A-Z]{2}\d{3}/g
AB123 cd456 EF789

Expected result

AB123
EF789

Enter [A-Z]{2}\d{3} as the pattern, enable g and use the second line as test text. Uppercase prefixes match; cd456 does not. Enable i to compare case-insensitive behavior.

Scope and limitations

  • Separate slash delimiters from the pattern itself. Escaping in a JavaScript string literal is different from entering a regex pattern.
  • Expensive backtracking can freeze the browser. Start with a short sample, then expand it. Other languages may use engines with different behavior.

Does a result differ from this reference? Share steps without private data. Report a problem

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