Ruby anchors
Input
{"pattern":"\\A(?<word>\\w+)","text":"hello\nworld","ignoreCase":false,"dotMatchesNewline":false,"extended":false}Output
hello
Ruby Regex Tester
Try Ruby-style regular expressions against sample text and inspect matches, indexes, lengths, and capture groups.
Developer tools
What it helps with
- Check Ruby regex snippets before using them in Rails or scripts
- Inspect capture groups and match indexes
- Compare Ruby-style regex behavior with JavaScript regex behavior
How to use
- Enter a Ruby-style regular expression pattern.
- Paste sample text and choose i / m / x options when needed.
- Run the test and review matches, indexes, highlights, and capture groups.
Examples
Named captures
Input
{"pattern":"(?<key>\\w+)=(?<value>\\d+)","text":"id=42 count=7","ignoreCase":false,"dotMatchesNewline":false,"extended":false}Output
id=42, count=7
Dot matches newline
Input
{"pattern":"start.*end","text":"start\nline\nend","ignoreCase":false,"dotMatchesNewline":true,"extended":false}Output
start\nline\nend
Good to know
- Uses Oniguruma with Ruby syntax, not a full Ruby runtime.
- Ruby version and Onigmo differences may still matter for edge cases.
- Some patterns can be slow in the browser.
- Shows the first 500 matches.
- This tool is for testing, not security validation.
FAQ
- Is this the same as the JavaScript Regex Tester?
- No. This tool uses an Oniguruma engine with Ruby syntax, while the regular Regex Tester uses JavaScript RegExp.
- Does it run Ruby code?
- No. It only tests regular expression patterns against sample text.
- Is it a complete replacement for Ruby itself?
- No. It is useful for Ruby-style pattern checks, but Ruby version and Onigmo edge cases can still differ.
Related tools
Nearby utilities from the KoguNavi toolbox.