Regex Tools

Online Regex Tester

Online Regex Tester runs a JavaScript regular expression against your text in the browser, with live match highlighting, a count, and capture groups.

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

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

Test text
Matches





  
How to use Online Regex Tester

  
    
      
  1. Drop your pattern and test string into the field at the top of Online Regex Tester.
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  2. Tune the Pattern, Flags controls before you check.
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  3. Online Regex Tester updates the output automatically as you type.
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  4. Use Copy matches to keep or reuse the result.
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About this tool

  
Online Regex Tester is a static, client-side tool with no backend. Online Regex Tester tests your regular expression against sample text in your browser, highlighting matches as you type.

  
Flags and group captures are surfaced so you can refine the pattern quickly. It behaves the same on desktop and mobile, with nothing stored remotely.

  
Frequently asked questions

  

      
What is Online Regex Tester for?
Use Online Regex Tester to check your input without installing anything using the Pattern, Flags controls; everything happens client-side.

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

      
Is my input private in Online Regex Tester?
Yes — your input never leaves your device; Online Regex Tester does all the work in your browser.

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

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

  

  
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