Regular Expression Tester
Test a regular expression in JavaScript, in PCRE as PHP runs it, in Go, in Rust, or in GNU sed and grep, with every match and group colored, explained step by step, and drawn as a diagram.
Pattern
empty
Test text
empty
Result
PCRE is PCRE2 10.44, as PHP 8.5 bundles it. Only JavaScript counts offsets in UTF-16 units; the rest count bytes.