Text & Code

How to Test a Regular Expression

Step-by-step guide to writing, testing, and debugging regular expressions using the DevHexLab Regex Tester.

Tool Used

Regex Tester

Open tool
1

Open the Regex Tester

Navigate to /tools/text/regex-tester.

2

Enter the regex pattern

Type your regular expression into the pattern field. You can set flags such as case-insensitive (i), global (g), and multiline (m).

3

Paste the test string

Enter the text you want to test against in the test string area. Matches are highlighted in real time as you type.

4

Review match details

The tool shows every match, the capture group values, and the index positions of each match. Use this to refine your pattern until it captures exactly what you need.

All done!

You are ready to use Regex Tester like a pro.

Try it now
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