Test and debug regular expressions
Test regex patterns with real-time matching and highlighting
Regex Cheatsheet
.Any character\dDigit [0-9]\wWord char [a-zA-Z0-9_]\sWhitespace^Start of string$End of string*0 or more+1 or more?0 or 1{n}Exactly n{n,m}Between n and m[abc]Any of a, b, c[^abc]Not a, b, c(abc)Capture groupa|ba or b(?:abc)Non-capture groupHow to Test Regular Expressions
Debug and validate regex patterns with real-time matching, group highlighting, and a built-in cheat sheet. Perfect for developers working with text patterns.
Enter Your Pattern
Type your regex pattern in the pattern field. Select flags like global (g), case-insensitive (i), or multiline (m).
Add Test Text
Paste or type the text you want to match against. See matches highlighted instantly as you type.
Analyze Matches
View all matches, capture groups, and their positions. Use the cheat sheet for pattern reference.
Why Use DevSensei?
What makes DevSensei different from other tools
Real-Time Matching
See matches highlighted instantly as you type. No need to click 'test' - results update live.
Group Highlighting
Capture groups are color-coded for easy identification. See exactly what each group matches.
Built-in Cheat Sheet
Quick reference for common patterns, quantifiers, and special characters. Learn regex as you build.
Frequently Asked Questions
Common questions about this tool
Common issues: forgetting to escape special characters (use \. for literal dot), missing the global flag for multiple matches, or case sensitivity (add 'i' flag). Check our cheat sheet for syntax help.
Use capture groups by wrapping parts of your pattern in parentheses. For example, (\d{4})-(\d{2})-(\d{2}) captures year, month, and day separately from a date string.