DevConvertor

Regex Tester

Test a regular expression against a sample string with live match highlighting, capture groups, flag toggles, and a replace mode. Includes ready-made examples for common patterns like email addresses and URLs.

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Examples

ReadyDeveloper UtilitiesFree · No account required

Related tools

Regex GeneratorBuild a regular expression from structured building blocks.Text Diff CheckerCompare two pieces of text, side by side or as a unified diff.Case ConverterConvert text between upper, lower, title, camelCase, snake_case, and more.

Features

  • Live match highlighting as you type, with a running match count
  • i / m / s / u flag toggles
  • Capture group and named-group details per match
  • Replace mode with $1-style group references
  • Ready-made examples for email, URL, numbers, dates, and more

How to use

  1. Enter a pattern and toggle any flags you need.
  2. Paste a test string — matches highlight automatically.
  3. Switch on Replace mode to preview a substitution.

Example

An invalid pattern (like an unclosed character class) shows the engine's error message instead of silently failing, so you can fix the syntax and keep going.