Qlopedia

Open web technology documentation website from Mozilla

MDN Web Docs

MDN Web Docs is a popular developer documentation website for HTML, CSS, JavaScript, Web APIs, accessibility, browser compatibility, and other open web technologies.

Core use
MDN Web Docs helps developers learn and reference open web technologies such as HTML, CSS, JavaScript, HTTP, Web APIs, and accessibility.
Free resource
MDN describes itself as a free-to-use resource that documents open web technologies.
Community documentation
MDN content is maintained through Mozilla and a broader contributor community, with public guidelines and open documentation workflows.
MDN Web Docs documents HTML, CSS, JavaScript, Web APIs, compatibility data, and other open web technologies.View image on original site

What MDN Web Docs is

MDN Web Docs is a free developer documentation website for open web technologies. On MDN Web Docs, developers can look up HTML, CSS, JavaScript, HTTP, Web APIs, browser compatibility data, accessibility guidance, tutorials, and reference material for building websites and web apps.

Web platform reference

MDN is best known as a reference for the web platform. Its pages explain browser features, syntax, examples, compatibility notes, specifications, and practical usage details that help developers understand how web technologies work across browsers.

HTML, CSS, JavaScript, and APIs

The site covers core building blocks such as HTML elements, CSS properties, JavaScript language features, HTTP headers, browser APIs, accessibility patterns, and progressive web app concepts. Many pages include examples and links to related standards or guides.

Learning guides

MDN is not only a lookup site. It also includes learning paths, tutorials, guides, and conceptual introductions for people building web projects. These materials help bridge the gap between a quick reference page and a larger course or textbook.

Compatibility and standards context

Browser compatibility tables are one of MDN’s most useful features. They help developers see whether a feature works in different browsers and versions, while specification links give readers a path from practical documentation to formal standards work.

Why it matters

MDN Web Docs matters because the web is shared infrastructure. Developers need neutral, detailed, and current documentation to build sites that work across devices, browsers, assistive technologies, and changing platform features.

Limits and cautions

MDN is an excellent reference, but developers should still test in real browsers, read relevant specifications or vendor docs when precision matters, check compatibility dates, and confirm behavior in the versions their users actually run.

WHOIS domain data

Data pulled: May 20, 2026View current WHOIS record

Domain
mozilla.org
IP address
35.190.14.201
Registrar
MarkMonitor Inc.
WHOIS server
whois.markmonitor.com
Referral URL
http://www.markmonitor.com
Created
January 24, 1998
Updated
December 22, 2024
Expires
January 23, 2027
Nameservers
ns4-64.akam.net (84.53.139.64); ns5-65.akam.net (184.85.248.65); ns1-240.akam.net (193.108.91.240); ns7-66.akam.net (96.7.49.66)
Domain status
clientDeleteProhibited; clientTransferProhibited; clientUpdateProhibited
Registrant contact
Name is listed as DNS Admin; organization is Mozilla Corporation; address is listed as San Francisco, CA, US; email is hostmaster [at] mozilla [dot] com.