About RegExr
RegExr is a web tool for writing, testing and learning regular expressions. Results update as you type, so you can see each match and capture group right away.
What it does
You enter a pattern and sample text, and the matches are highlighted with details for each token. The explain tool describes the expression in plain language. Patterns can be saved and shared, and community patterns can be searched and rated.
Key features
- Live match highlighting as you type
- JavaScript and PCRE flavors
- Test suites to check a pattern against samples
- Explain mode describes tokens in plain English
- Replace and list tools for match output
- Cheatsheet and full reference in the sidebar
Who it's for
Developers writing validation or parsing code, students learning regex syntax and testers building input checks. It helps to see how a pattern behaves on real examples.
Pricing and good to know
RegExr is open source under the GPL-3.0 license and is free for all levels, according to the site. It supports JavaScript and PCRE syntax, which can differ in small ways from other regex engines. Check the flavor used by your target language before copying a pattern into production code.
Highlights
- Live match highlighting as you type
- JavaScript and PCRE flavors
- Test suites to check a pattern against samples
- Explain mode describes tokens in plain English
- Replace and list tools for match output
- Cheatsheet and full reference in the sidebar
