Regex tester

This tool compiles the pattern with selected flags and reports every match and capture position. The complete operation runs in temporary browser memory, so the input is never uploaded or stored by LocalKit.

Local processing
Local processing
Ready — nothing leaves this page
Input
Settings
Run tool

Browser memory only. No upload fallback.

Result
Your result will appear here

The input stays available if you need to adjust a setting.

How to use regex tester

  1. 1

    Add the source values or files shown in the workbench.

  2. 2

    Choose the settings for regex tester.

  3. 3

    Run the tool, inspect the local result, then copy or download it.

A realistic example

Find capitalized words globally and inspect their indexes and capture groups. The source and generated result remain in this browser tab throughout the operation.

Supported formats and limits

Input: JavaScript regex pattern, flags, and UTF-8 text. Output: formatted match report.

  • Patterns use JavaScript regular-expression syntax and can still be computationally expensive.
  • Available memory and browser limits still apply to very large inputs.

Questions people ask

What does regex tester change?

This tool compiles the pattern with selected flags and reports every match and capture position.

Is any input sent to a server?

No. LocalKit performs this operation in your current browser tab.