Regular Expression Tester
Regular Expression Tester
Inspect bounded PCRE matches and capture groups on a UTF8 text sample.
A pattern needs representative examples before it is used on a real dataset.
Test a small UTF8 sample and inspect matches, groups and byte positions.
How to use Regular Expression Tester
- Choose modifiers. Enter pattern body.
- Paste or enter text to inspect.
- Select Process input. Read the returned values alongside the assumptions below before copying, exporting or acting on the result.
Why choose this tool?
Bounded PCRE matching keeps the test focused and exposes captured values.
Before you use the result
Up to 100 matches. Byte offsets are shown. Backtracking and recursion limits bound work; this is PCRE, not JavaScript regex.
Questions about Regular Expression Tester
Will the pattern behave identically in JavaScript?
Not necessarily. This tester uses PHP PCRE, whose rules can differ from JavaScript regular expressions.
What should I check before using Regular Expression Tester?
Check Pattern body, Modifiers and Text to inspect. Use the exact units shown beside the controls and replace any example values with your own inputs.
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