Regex Tester - Free Online Tool
Test regex patterns with live matching and highlighting for free. See all matches, groups, and index positions. Common pattern presets included.
Test regular expressions with live matching, highlighting, and group extraction
Regex Tester Features
- Live Matching: See matches highlighted in real-time as you type
- Match Details: View all matches with groups and index positions
- Common Patterns: Quick-insert presets for email, URL, phone, IP, date
- Flag Support: Toggle global, case-insensitive, multiline, dotAll flags
How to Use Regex Tester
Test regex patterns in three steps
- Step 1: Enter Pattern — Type your regex or pick a common preset
- Step 2: Enter Test String — Paste text to test against
- Step 3: View Matches — See highlighted matches and group details
Frequently Asked Questions about Regex Tester
Is this regex tester free?
Yes, completely free with no signup. All testing happens in your browser using JavaScript's RegExp engine.
Which regex engine does it use?
JavaScript's built-in RegExp engine — the same one used in browsers and Node.js. Syntax may differ slightly from PCRE (PHP/Python).
What flags are supported?
Global (g), case-insensitive (i), multiline (m), and dotAll (s). Toggle them with the flag buttons.
Does it show capture groups?
Yes! Each match shows its captured groups with labels (Group 1, Group 2, etc.) along with the full match and index position.
What common patterns are included?
Email, URL, phone (India), IPv4, date (DD/MM/YYYY), hex color, HTML tags, and numbers. Click any preset to auto-fill the pattern.
Is my test data safe?
Yes, everything runs locally in your browser. No data is sent to any server.
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