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DEVELOPER TOOLS
Fast, client-side web development tools and technical syntax guides built with zero external dependencies, zero advertisements, and full ECMAScript compliance.
JAVASCRIPT REGULAR EXPRESSION SUITE
JavaScript Regular Expression Tester
Test regular expressions against multiline text in real time. Inspect full matches, numbered capture groups ($1, $2), named groups ((?<name>...)), character offsets, line/column positions, and live String.replace() output.
- ✓ Real-time client-side ECMAScript RegExp evaluation
- ✓ Interactive flag toggles (g, i, m, s, u, y, d) & pattern presets
- ✓ Instant syntax error diagnostics & JSON/JS export
JavaScript Regex Guide: Syntax, Examples & Patterns
Comprehensive developer handbook covering regular expression literals vs constructors, anchors, greedy vs lazy quantifiers, character classes, Unicode property escapes (\p{...}), lookaround assertions, and ReDoS prevention.
- ✓ Complete syntax tables for anchors, quantifiers & groups
- ✓ Practical code examples for test(), exec(), matchAll() & replace()
- ✓ Performance & catastrophic backtracking security guide
PRESERVING THE APHEX CREATIONS DEVELOPER TOOLKIT
Our interactive JavaScript Regex Tester serves as the permanent modern successor to REJAX (projects.aphexcreations.net/rejax/), originally launched in February 2007 by Brendon Crawford at Aphex Creations. Explore our preserved historical documentation and modern engineering guides: