RegexLab is a lightweight, in-browser regex playground built to make testing and understanding regular expressions less painful.
It lets you write a regex, instantly see matches highlighted in real time, and get simple explanations for what different parts of the pattern are doing. Everything runs locally in the browser, no backend, no setup.
- Real-time regex matching and highlighting
- Plain-language explanations for common regex tokens
- Built-in library of commonly used regex patterns
- Shareable links that restore text and pattern state
- Clean, distraction-free UI
RegexLab uses JavaScript’s RegExp engine to test patterns against user-provided text. Matches are highlighted directly in the preview, and a small rule-based system explains the most common regex constructs when they appear in a pattern.
The current text and regex pattern are encoded into the URL, so sharing a link recreates the exact same state for anyone opening it.
regexlab/
├── index.html
├── style.css
└── script.js
No frameworks, no dependencies.
Clone the repository and open index.html in your browser.
git clone https://github.com/your-username/regexlab.git
cd regexlabRegex is powerful but often opaque. RegexLab focuses on making feedback immediate and understandable instead of treating regex like a black box.
- Support for regex flags (
i,m,g) via UI toggles - More detailed explanations for complex patterns
- Saving and exporting regex snippets
~ Ritwik Dadarwal