Derrick Foos's REGEX Tool

Test JavaScript regular expressions entirely in your browser with zero network calls. Built for DevOps workflows: paste logs, validate patterns, inspect capture groups, preview replacements, and copy structured match data. Save this HTML file locally and use it completely offline.

Flags:

Status

Enter a pattern and test text, then run the regex.
Matches: 0 Capture Groups: 0 Runtime: 0 ms

Highlighted Matches

Matches & Capture Groups

Replacement Preview



      

        Tip: JavaScript replacements support numbered groups like $1
        and named groups like $<name>.
      

    

  


  

    
DevOps Regex Snippets

    

      Click a snippet to load the pattern. These are intentionally practical starting points;
      tune them for your environment.
    

    

  


  

    
Quick Reference


    

      Capture group examples
      
(?\d{4}-\d{2}-\d{2}T[^\s]+)\s+(?INFO|WARN|ERROR)\s+(?.*)
(?\b(?:\d{1,3}\.){3}\d{1,3}\b)
status=(?[1-5]\d{2})

    


    

      Useful tokens
      
\d digit      \w word char      \s whitespace      . any char except newline
^ line start  $ line end       \b word boundary   .*? lazy any text
(?:x) non-capturing group      (?x) named capture group

    


    

      Offline privacy note
      

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