MDN’s refreshed JavaScript regular expression reference gives developers a focused entry point for each regex feature, presenting syntax, semantics, examples, and browser support in a single, searchable page.

Overall Page Layout

The top‑level reference page groups the 18 feature pages under logical categories, making it easy to jump directly to the topic you need.

• Sidebar navigation mirrors the category tree for fast access.
• Each feature page starts with a concise definition followed by a syntax table.
• Compatibility tables list support per browser version.
• Example blocks demonstrate real‑world usage.
• Links to related MDN articles appear at the bottom.

Feature Pages: Syntax & Semantics

Every regex construct—such as quantifiers, character classes, or look‑arounds—receives its own page that explains the grammar and edge cases.

• Clear syntax diagram generated from the ECMA‑262 specification.
• Explanation of semantic nuances, e.g., greedy vs. lazy quantifiers.
• Common pitfalls highlighted with warnings.
• Sample code snippets that can be copied directly.
• Reference to the regular expression concept for background.

Browser Compatibility Information

Granular compatibility tables let you see exactly which versions implement a given feature, reducing guesswork for polyfills.

• Data sourced from MDN compatibility tables.
• Separate rows for desktop and mobile browsers.
• Notes on partial support or required flags.
• Links to Can I Use for quick cross‑check.
• Visual indicator for deprecated or removed features.

Practical Examples & Patterns

Each page includes a handful of curated examples that illustrate typical use cases, from date parsing to Unicode script detection.

• Capturing groups example for ISO dates (YYYY‑MM‑DD).
• Named capturing groups to improve readability of log‑parsing regexes.
• Unicode property escapes for script detection (e.g., /\p{Script=Latin}/u).
• Character class range example for hexadecimal validation.
• Link to a broader JavaScript performance guide: Accelerate JavaScript Development with Bun.

Contribution Workflow

New pages were created after a community discussion on GitHub, followed by iterative pull requests and review cycles.

• Initial feedback collected via a GitHub discussion.
• Drafted scaffold added by Joshua Chen.
• Multiple review rounds ensured accuracy and completeness.
• Changes merged into the MDN content repository and published.
• For developers interested in set operations, see the upcoming v‑flag proposal illustrated in New JavaScript Set Methods.