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Regex Validator

Check that a regular expression is valid and see whether it works as you expect.

How it works Report a problem

Regex Syntax Validator

Instantly verify the integrity and compatibility of your regular expression patterns

SYNTAX PRO
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About the Regex Validator

Check that a regular expression is valid and see whether it works as you expect.

How to use the Regex Validator

  1. Enter the Regex Pattern and the Flags (such as g, i or m).
  2. Press Validate Syntax Integrity.
  3. Read the result and fix any error reported.

Worked example

^([a-zA-Z]+)$ matches "Hello" but not "Hello1", because digits are not allowed.

Tips

  • Flags: g = all matches, i = ignore case, m = multiline.
  • Unbalanced brackets and unescaped special characters are the most common errors.

Frequently asked questions

What does the i flag do?
It makes the pattern ignore upper and lower case.