Regex Tester
Use Regex Tester
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Regex Tester
Test String
Test Cases
Match Result
Matches
Explanation
About this tool
Test regular expressions in real time with live matches, highlighting, explanations, and reusable test cases.
- Your input never leaves the browser
- Handles large files and batch input
- Customizable formatting and indent options
- Free and unlimited, no sign-up
Compared with IDE plugins or CLI tools
| Aspect | This tool | Typical alternative |
|---|---|---|
| Iteration speed | Better for quick paste-and-check loops | Deeper integration, heavier startup |
| Sharing | Easier to share samples and outputs | Better for longer engineering workflows |
| Environment dependency | Only needs a modern browser | Often depends on editor and local setup |
Docs
Test regular expressions in real time with live matches, highlighting, explanations, and reusable test cases.
Main Features
- Real-time matching: Enter regex pattern and test string, view matches instantly
- Highlight display: Matched content highlighted in the original text
- Syntax explanation: Automatically explains each part of the regex
- Multi-flag support: Supports g/i/m/s/u and other common flags
- Test cases: Add multiple test cases for batch validation
- Common patterns: Built-in patterns for email, URL, phone, IP address
- Capture group display: Clearly shows content of each capture group
How to Use
- Enter a pattern in the regex input field (e.g.,
\d+) - Enter text to match in the test string field
- Select desired matching flags
- View real-time highlighted results and match details
- Use “Common Patterns” to quickly insert frequently used regex
Technical Features
- Pure frontend implementation, no backend required
- Based on browser native RegExp API
- Supports all major regex syntax
- Responsive design for desktop and mobile
Use Cases
- Writing form validation regex in frontend development
- Data cleaning and extraction rule debugging
- Regex learning and teaching
- Combine with JSON tools for structured data processing
Last verified: 2026-04-07 Source: SunneV/OpenRegex
FAQ
Is it free?
Yes, completely free. No signup, no limits.
How to use?
Enter regex pattern and test text. Real-time highlighting with match groups.
Will data be saved?
No. All local. Never uploaded.
Common patterns available?
Yes. Library includes email, phone, URL patterns for quick reference.
What syntax supported?
Browser-native JS engine. All standard regex: groups, assertions, quantifiers.
Is this tool better for debugging, learning, or pre-production checks?
All three. Debugging benefits from fast iteration, learning benefits from immediate visual feedback, and pre-production checks benefit from validating formatting, syntax, and edge cases before deployment.
Will my code or data leave the browser?
Most developer tools here default to browser-side processing, which is better for code snippets, configs, and sensitive text. If any feature depends on a remote model or external API, that is explicitly called out on the page.
How is this different from an IDE plugin or command-line tool?
A web tool is usually faster for quick validation, link sharing, and cross-device use. IDE plugins and CLI tools are stronger when you want the capability embedded into a longer engineering workflow.
Do I need to sign up, download, or install anything?
Most Gotokit tools are designed to open directly in the browser without a separate install. If a tool has a quota, browser requirement, or third-party dependency, the page copy will state that clearly.
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