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Regex Tester

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Regex Tester — Test Regular Expressions Online Free

What is Regex Tester?

Test regular expressions. First line: regex pattern. Remaining lines: text to test. Shows all matches.

Paste a regex on the first line and sample text below. See all matches and groups. Client-side only.

How to Use Regex Tester

  1. Paste or type your input into the editor on the left panel.
  2. Results update automatically while you type. You can also press Ctrl+Enter to force a refresh.
  3. View the result in the output panel on the right with full syntax highlighting.
  4. Use Copy or Download to export the result.
  5. Drag and drop .json or .txt files directly into the editor.

Example

Input:

/\w+/g
Hello world 123

Output:

Match: "Hello" at index 0...

Common Use Cases

  • Validate patterns
  • Extract matches
  • Learn regex

Common Errors

    Why Use Our Regex Tester?

    • 100% client-side — your data never leaves your browser. No server processing, no data collection.
    • No sign-up required — start using the tool instantly with no registration or installation.
    • Keyboard shortcuts — press Ctrl+Enter to run, ? for shortcuts list, Ctrl+B to toggle sidebar.
    • Persistent state — your input is automatically saved across sessions using local storage.
    • IDE-style interface — Monaco Editor (the engine behind VS Code) with syntax highlighting and error detection.
    • Multi-format conversion — convert between JSON, XML, CSV, and YAML without switching tools.

    Frequently Asked Questions

    How do I use it?

    First line: your regex (e.g. \d+ or /pattern/g). Next lines: text to search.

    Try Regex Tester Now

    Paste your data into the editor above for instant processing. Use Ctrl+Enter anytime to re-run quickly.

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