Regex Tester

Free online regex tester to test regular expressions and inspect matches quickly.

  • Runs locally in your browser
  • No data uploaded
  • Instant processing
Waiting for input

How to Use Regex Tester

  1. Set line 1 as pattern and line 2 as flags.
  2. Put test text from line 3 onward.
  3. Inspect each regex match and its index in output.

Example Usage

Input

pattern: \b[a-z]+\b
flags: gi
Hello 123 world

Output

#1: "Hello" at index 0
#2: "world" at index 10

Frequently Asked Questions

Which regex flags are supported?
g, d, i, m, s, u, v, and y flags are supported.
Do I need global flag for all matches?
No. The tester ensures global matching when listing all results.
What if my pattern is invalid?
The tool returns a clear regex syntax error.