Regex Tools

Regex C Tester

Regex C 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.

Regex C 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 Regex C Tester

  
    
      
  1. Drop your pattern and test string into the field at the top of Regex C Tester.
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  2. Adjust the POSIX pattern option to match what you need.
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  3. Regex C Tester updates the output automatically as you type.
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  4. Use Copy pattern to keep or reuse the result.
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About this tool

  
Regex C Tester runs entirely in your browser. Regex C Tester runs your pattern locally with the JavaScript engine and shows captures live.

  
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 Regex C Tester?
Regex C Tester lets you check your input right in the browser using the POSIX pattern control, with the result shown instantly and nothing uploaded.

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

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

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

      
Does Regex C Tester work offline?
Once the page has loaded, Regex C Tester keeps working with no network connection.

  

  
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