IT & Developers
Regex Tester
Test and debug regular expressions
Created and maintained by: CalcTago Editorial TeamLast updated: 2026-02-09
Formulas and edge cases are reviewed against authoritative references before publication. For methodology, editorial standards, or corrections, use the links below.
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Frequently asked questions
What does the Regex Tester do?
It helps you test and debug regular expressions.
What inputs do I need?
Enter Pattern and Flags.
Are decimals supported?
Yes, you can use decimal values where appropriate.
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About this tool
This Regex Tester turns your inputs into practical results. Provide Pattern, Flags, and Test text to calculate Error and Match count.
Adjust values to compare scenarios and see how sensitive the result is. The calculation uses the numbers as entered, so double-check units and expect small differences from rounding in the displayed totals.