Regex Tester
Test, debug, and visualize regular expressions in real-time β no lag, instant results
How to Use Regex Tester
Test, debug, and master regular expressions β complete developer guide
β‘ Test Regular Expressions in 3 Simple Steps
Enter Your Pattern
Type your regex pattern (e.g., \b\d{3}-\d{2}-\d{4}\b) in the Regular Expression field. Use common patterns from the chips below.
Add Test Text
Paste or type the text you want to search in the Test String area. The matches will be highlighted in real-time as you type.
Copy Results
Click Copy Matches to save all matched values. Use the flags (g, i, m, s, u) to modify how your regex behaves.
Regular expressions (regex) are powerful patterns for searching, matching, and manipulating text. They're essential for validation, parsing, search/replace, and data extraction in programming.
Key features include: real-time matching with visual highlighting, support for all regex flags (g, i, m, s, u), capture group extraction, common pattern library, error detection, and 100% client-side processing.
β Everything You Need to Know
g (global) β find all matches, not just the first. i (case-insensitive) β ignores case when matching. m (multiline) β treats ^ and $ as line boundaries. s (dotall) β allows . to match newlines. u (unicode) β enables full Unicode support.
Capture groups () extract specific parts of a match. For example, in (\d{3})-(\d{2})-(\d{4}), each set of numbers becomes a separate captured group. Our tool displays all captured groups for each match.
Yes! All regex testing happens locally in your browser. No patterns or text are ever sent to any server β your data stays completely private.
100% free β no signup required! Test unlimited regex patterns. No hidden fees, no premium tiers. We believe essential developer tools should be accessible to everyone.
