A curated, versioned reference for ECMAScript regular expressions: characters and escapes, character classes and Unicode properties, anchors, quantifiers, groups and back-references, lookaround, flags (g i m s u v y d), the JavaScript API and common pitfalls (including ReDoS). Every entry carries a runnable example verified in Node.js. Search by token, flag or words, or pick a section. Source, version and review date are printed with every result. Everything runs locally.