ECMAScript RegExp Engine
Online Regex Tester & Playground
Test regular expressions against sample text with real-time match groups and flags. Write code with auto-formatting, test with standard input (stdin), and inspect terminal output in real-time.
✓ Global, multiline, and case-insensitive flags✓ Capture group and named group extraction✓ Instant match counts and highlights✓ Zero server roundtrips
pattern.regex
ECMAScript RegExp Engine13px
Output & ConsoleIdle
Ready to Compile & Run
Click the blue ▶ Run button in the header bar or press Ctrl + Enter to compile and execute your Online Regex Tester & Playground.
How to Run Regex Tester Code Online
Enter a regular expression pattern in the editor and test strings in the Stdin drawer.
- Enter your regex pattern in the code editor.
- Enter target test text in the Stdin drawer.
- Click "▶ Run" to extract matches and capture groups.
Common Errors & Troubleshooting
Encountering compilation or runtime diagnostics? Check these common scenarios:
Invalid regular expressionEscape unclosed parentheses or brackets with backslashes.Related Markup & Configuration Playgrounds
View all 35+ compilers →Frequently Asked Questions (Regex Tester)
Yes, match indices and capture group contents are highlighted.