VI · Developer & Web
VI · Developer & WebAV-W01

AV-W01

Regex Tester

Test JavaScript regular expressions with highlighted matches, capture groups, replace preview and a plain-English explanation.

● Runs on your device; nothing is uploaded

How to use it

  1. Type a pattern between the slashes and set flags in Flags or with the flag buttons.
  2. Paste your sample into Test text; matches are highlighted as you type.
  3. Check the match table for positions and capture group values.
  4. Enter a Replacement to preview the replaced text, then copy it.
  5. Read the Explanation panel for a plain-English breakdown of the pattern.

Limits

Test text
1,000,000 characters
Matching time
1 second per run
Matches collected
5,000
Highlighted matches
First 2,000
Match table rows
First 500
Features
  • Matching runs in a Web Worker, so a runaway pattern can be stopped
  • Numbered and named capture groups with start and end positions
  • Replace preview with amp;, $1, lt;name> and $ tokens
  • Supports the d, g, i, m, s, u, v and y flags
  • Token-by-token explanation of the pattern

For AI agents: avtools_regex_tester

AV-W01 · Regex Tester

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