Free Regex Tester and Formatter

Test regex patterns, inspect matches, and format expressions for readability.
No uploads. No servers. No account required.

100% Private - Input Never Leaves Your Device

Regex compilation, matching, and formatting run locally in your browser only.

Regex Tester

Flags

Matches update automatically while you type.

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Supports JavaScript replacement tokens like $1, $2, $<name>, $&, and $$.

Saved Snippets

Regex Formatter

Formatting is for readability only and does not change your active test pattern.

Quick Reference

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    How to Use

    1. Enter a regex pattern and select needed flags.
    2. Type test string input and review highlighted matches.
    3. Use replace preview, explanation, and snippets for reuse.

    Example: Find all invoice IDs and preview replacement output safely. See full use case.

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    Related Tools

    Common next steps for this workflow: