Free Online Regex Tester
Real-time match highlighting, capture group display, and a handy cheatsheet. Runs entirely in your browser.
Key Features
Real-time Matching
Matches and highlights automatically as you type the regex and text β no button clicks needed.
Capture Group Display
Clearly shows each match's captured groups, making debugging easy at a glance.
Handy Cheatsheet
Built-in common regex snippets β character classes, quantifiers, and assertions.
Local Processing
Everything runs locally in the browser; your regex and text are never uploaded.
How to Use
Enter Regex
Type your regex on the left and select options (global, case-insensitive, etc.) as needed.
Paste Test Text
Type the text to test on the right; matches are highlighted in real time.
Review Capture Groups
Each match's details and capture groups are listed below for easy debugging.
Frequently Asked Questions
What is a regular expression?
A regular expression (regex) uses special characters to describe a string matching pattern, commonly used for validating emails, extracting data, and replacing text.
Why is it recommended to enable the global option?
The g flag searches all matches across the whole text; otherwise only the first match is returned by default. Enable it for most extraction tasks.
How do I use capture groups?
Parentheses ( ) in a regex define capture groups. The tool lists each group's captured content separately to help you understand the grouping results.
Are my regex and text uploaded?
No. All matching happens locally in your browser, and your content never leaves the device.