Regex Tester Online with Explanation
Regular expressions are powerful but notoriously tricky to get right. Our online regex tester lets you write a pattern and instantly see all matches highlighted in your test string. View captured groups, toggle flags (global, case-insensitive, multiline), and iterate on your regex until it works perfectly — all in real time without running any code.
Try Emoji Picker NowHow to Test Regular Expressions Online
- 1 Open the Regex Tester tool.
- 2 Enter your regular expression pattern in the pattern field.
- 3 Set flags (g for global, i for case-insensitive, m for multiline).
- 4 Paste or type your test string in the text area.
- 5 See all matches highlighted instantly with captured group details.
Why Use Our Regex Tester
- Real-time matching — see results as you type your pattern.
- Captured groups are displayed so you can verify your pattern extracts the right data.
- Toggle flags easily without editing the pattern syntax.
- Works with JavaScript regex syntax used in most web applications.
- Free, instant, and requires no account.
Ready to Get Started?
Our Emoji Picker is free, fast, and works right in your browser. No sign-up needed.
Use Emoji Picker FreeFrequently Asked Questions
The tool uses JavaScript regex syntax, which is the most widely used flavor in web development. It supports lookahead, lookbehind (in modern browsers), character classes, quantifiers, and all standard regex features.
Yes. Enable the multiline (m) flag to make ^ and $ match the start and end of each line rather than the entire string.
Capture groups are parts of a regex pattern enclosed in parentheses. They extract specific portions of the matched text. Our tool shows each capture group separately so you can verify your pattern.