Regex Tools

C Regex Tester

C Regex Tester approximates POSIX ERE/BRE regular expressions in your browser and shows a matching regcomp/regexec C snippet for reference.

Client-sideRuns entirely in your browser — your data never leaves your device.

C Regex Tester is a free Regex Tools utility that runs entirely in your browser — nothing you enter is uploaded.

Test text
Matches




C — regcomp() / regexec()



  
How to use C Regex Tester

  
    
      
  1. Paste the pattern and test string you need to check into the input box.
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  2. Adjust the POSIX pattern option to match what you need.
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  3. Watch the output update instantly while you adjust the pattern and test string.
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  4. Use Copy pattern to keep or reuse the result.
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About this tool

  
Everything C Regex Tester does happens on your own device. C Regex Tester tests your regular expression against sample text in your browser, highlighting matches as you type.

  
Your pattern and test text stay on your device. Your input never leaves the page, and no account or install is required.

  
Frequently asked questions

  

      
How do I use C Regex Tester?
C Regex Tester runs entirely on your device: add your input using the POSIX pattern control, and it checks it locally in real time.

      
Does C Regex Tester cost anything?
No — C Regex Tester is completely free, with no sign-up and no hidden limits.

      
Where is my data processed by C Regex Tester?
Entirely in your browser — C Regex Tester keeps your data on your own machine and sends nothing anywhere.

      
Which regex flavor does C Regex Tester use?
C Regex Tester runs your pattern with the browser's own JavaScript regex engine, live and on your device.

      
Does C Regex Tester work on mobile?
Yes — C Regex Tester is just a web page and runs on any modern browser, including phones and tablets.

  

  
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