HTML5 is a markup language used for structuring and presenting content on the World Wide Web. It is the fifth and final major HTML version that is a World Wide Web Consortium (W3C) recommendation. The current specification is known as the HTML Living Standard. It is maintained by the Web Hypertext Application Technology Working Group (WHATWG), a consortium of the major browser vendors (Apple, Google, Mozilla, and Microsoft).
|Internet media type|
|Uniform Type Identifier (UTI)||public.html|
|Initial release||22 January 2008|
|Type of format||Markup language|
HTML5 was first released in a public-facing form on 22 January 2008, with a major update and "W3C Recommendation" status in October 2014. Its goals were to improve the language with support for the latest multimedia and other new features; to keep the language both easily readable by humans and consistently understood by computers and devices such as web browsers, parsers, etc., without XHTML's rigidity; and to remain backward-compatible with older software. HTML5 is intended to subsume not only HTML 4 but also XHTML 1 and DOM Level 2 HTML.
HTML5 includes detailed processing models to encourage more interoperable implementations; it extends, improves, and rationalizes the markup available for documents and introduces markup and application programming interfaces (APIs) for complex web applications. For the same reasons, HTML5 is also a candidate for cross-platform mobile applications because it includes features designed with low-powered devices in mind.
Many new syntactic features are included. To natively include and handle multimedia and graphical content, the new
<canvas> elements were added, expandable sections are natively implemented through
<figure> are added. New attributes were introduced, some elements and attributes were removed, and others such as
<menu> were changed, redefined, or standardized. The APIs and Document Object Model (DOM) are now fundamental parts of the HTML5 specification, and HTML5 also better defines the processing for any invalid documents.
The Web Hypertext Application Technology Working Group (WHATWG) began work on the new standard in 2004. At that time, HTML 4.01 had not been updated since 2000, and the World Wide Web Consortium (W3C) was focusing future developments on XHTML 2.0. In 2009, the W3C allowed the XHTML 2.0 Working Group's charter to expire and decided not to renew it.
The Mozilla Foundation and Opera Software presented a position paper at a World Wide Web Consortium (W3C) workshop in June 2004, focusing on developing technologies that are backward-compatible with existing browsers, including an initial draft specification of Web Forms 2.0. The workshop concluded with a vote—8 for, 14 against—for continuing work on HTML. Immediately after the workshop, WHATWG was formed to start work based upon that position paper, and a second draft, Web Applications 1.0, was also announced. The two specifications were later merged to form HTML5. The HTML5 specification was adopted as the starting point of the work of the new HTML working group of the W3C in 2007.
"Thoughts on Flash"Edit
Last call, candidacy, and recommendation stagesEdit
On 14 February 2011, the W3C extended the charter of its HTML Working Group with clear milestones for HTML5. In May 2011, the working group advanced HTML5 to "Last Call", an invitation to communities inside and outside W3C to confirm the technical soundness of the specification. The W3C developed a comprehensive test suite to achieve broad interoperability for the full specification by 2014, which was the target date for recommendation. In January 2011, the WHATWG renamed its "HTML5" specification HTML Living Standard. The W3C nevertheless continued its project to release HTML5.
In July 2012, WHATWG and W3C decided on a degree of separation. W3C will continue the HTML5 specification work, focusing on a single definitive standard, which is considered as a "snapshot" by WHATWG. The WHATWG organization continues its work with HTML5 as a "living standard". The concept of a living standard is that it is never complete and is always being updated and improved. New features can be added but functionality will not be removed.
On 16 September 2014, W3C moved HTML5 to Proposed Recommendation. On 28 October 2014, HTML5 was released as a W3C Recommendation, bringing the specification process to completion. On 1 November 2016, HTML5.1 was released as a W3C Recommendation. On 14 December 2017, HTML5.2 was released as a W3C Recommendation.
The combined timelines for HTML5.0, HTML5.1, HTML5.2 and HTML5.3:
|Version||First draft||Candidate recommendation||Recommendation||Retired|
W3C and WHATWG conflictEdit
The W3C ceded authority over the HTML and DOM standards to WHATWG on 28 May 2019, as it considered that having two standards is harmful. The HTML Living Standard is now authoritative. However, W3C will still participate in the development process of HTML.
Before the ceding of authority, W3C and WHATWG had been characterized as both working together on the development of HTML5, and yet also at cross purposes ever since the July 2012 split. The W3C "HTML5" standard was snapshot-based (HTML5, HTML5.1, etc.) and static, while the WHATWG "HTML living standard" is continually updated. The relationship had been described as "fragile", even a "rift", and characterized by "squabbling".
In at least one case, namely the permissible content of the
<cite> element, the two specifications directly contradicted each other (as of July 2018),[update] with the W3C definition allowing a broader range of uses than the WHATWG definition.
The "Introduction" section in the WHATWG spec (edited by Ian "Hixie" Hickson) is critical of W3C, e.g. "Note: Although we have asked them to stop doing so, the W3C also republishes some parts of this specification as separate documents." In its "History" subsection it portrays W3C as resistant to Hickson's and WHATWG's original HTML5 plans, then jumping on the bandwagon belatedly (though Hickson was in control of the W3C HTML5 spec, too). Regardless, it indicates a major philosophical divide between the organizations:
For a number of years, both groups then worked together. In 2011, however, the groups came to the conclusion that they had different goals: the W3C wanted to publish a "finished" version of "HTML5", while the WHATWG wanted to continue working on a Living Standard for HTML, continuously maintaining the specification rather than freezing it in a state with known problems, and adding new features as needed to evolve the platform.
Since then, the WHATWG has been working on this specification (amongst others), and the W3C has been copying fixes made by the WHATWG into their fork of the document (which also has other changes).
The two entities signed an agreement to work together on a single version of HTML on 28 May 2019.
Differences between the two standardsEdit
In addition to the contradiction in the
<cite> element mentioned above, other differences between the two standards include at least the following, as of September 2018:
|Site pagination||Single page version (allows global search of contents)|
§10 Web workers
§11 Web storage
|Chapter Elements of HTML||§4.13 Custom elements|
||§22.214.171.124. Other pragma directives, based on deprecated WHATWG procedure.|
|§ Sections||§ 126.96.36.199 Sample outlines|
§ 188.8.131.52 Exposing outlines to users
|Structured data||Recommends RDFa (code examples, separate specs, no special attributes).||Recommends Microdata (code examples, spec chapter, special attributes).|
The following table provides data from the Mozilla Development Network on compatibility with major browsers, as of September 2018, of HTML elements unique to one of the standards:
||W3C||All browsers, except Edge|
||W3C||None, except Firefox|
||WHATWG||All browsers||"[Since] the HTML outline algorithm is not implemented in any browsers ... the |
||WHATWG||Full support only in Edge and Firefox desktop.
Partial support in Firefox mobile.
Supported in Opera with user opt-in.
Not supported in other browsers.
||WHATWG||All browsers, except IE||Experimental technology|
Features and APIsEdit
This section needs to be updated. The reason given is: Last sentence marks 2016 as the future instead of past.(October 2018)
The W3C proposed a greater reliance on modularity as a key part of the plan to make faster progress, meaning identifying specific features, either proposed or already existing in the spec, and advancing them as separate specifications. Some technologies that were originally defined in HTML5 itself are now defined in separate specifications:
- HTML Working Group – HTML Canvas 2D Context;
- Web Apps Working Group – Web Messaging, Web workers, Web storage, WebSocket, Server-sent events, Web Components (this was not part of HTML5, though); the Web Applications Working Group was closed in October 2015 and its deliverables transferred to the Web Platform Working Group (WPWG).
- IETF HyBi Working Group – WebSocket Protocol;
- WebRTC Working Group – WebRTC;
- Web Media Text Tracks Community Group – WebVTT.
Some features that were removed from the original HTML5 specification have been standardized separately as modules, such as Microdata and Canvas. Technical specifications introduced as HTML5 extensions such as Polyglot markup have also been standardized as modules. Some W3C specifications that were originally separate specifications have been adapted as HTML5 extensions or features, such as SVG. Some features that might have slowed down the standardization of HTML5 were or will be standardized as upcoming specifications, instead.
HTML5 introduces elements and attributes that reflect typical usage on modern websites. Some of them are semantic replacements for common uses of generic block (
<div>) and inline (
<span>) elements, for example
<nav> (website navigation block),
<footer> (usually referring to bottom of web page or to last lines of HTML code), or
<video> instead of
Some deprecated elements from HTML 4.01 have been dropped, including purely presentational elements such as
The HTML5 syntax is no longer based on SGML despite the similarity of its markup. It has, however, been designed to be backward-compatible with common parsing of older versions of HTML. It comes with a new introductory line that looks like an SGML document type declaration,
<!DOCTYPE html>, which triggers the standards-compliant rendering mode.
Since 5 January 2009, HTML5 also includes Web Forms 2.0, a previously separate WHATWG specification.
- Timed Media Playback;
- Editable content;
- Drag and drop;
- MIME type and protocol handler registration;
- Web Messaging;
- Web Storage – a key-value pair storage framework that provides behavior similar to cookies but with larger storage capacity and improved API.
Not all of the above technologies are included in the W3C HTML5 specification, though they are in the WHATWG HTML specification. Some related technologies, which are not part of either the W3C HTML5 or the WHATWG HTML specification, are as follows. The W3C publishes specifications for these separately:
- IndexedDB – an indexed hierarchical key-value store (formerly WebSimpleDB);
- File – an API intended to handle file uploads and file manipulation;
- Directories and System – an API intended to satisfy client-side-storage use cases not well served by databases;
- File Writer – an API for writing to files from web applications;
- Web cryptography API
- Web SQL Database – a local SQL Database (no longer maintained);
XHTML5 (XML-serialized HTML5)Edit
XML documents must be served with an XML Internet media type (often called "MIME type") such as
application/xml, and must conform to strict, well-formed syntax of XML. XHTML5 is simply XML-serialized HTML5 data (that is, HTML5 constrained to XHTML's strict requirements, e.g., not having any unclosed tags), sent with one of XML media types. HTML that has been written to conform to both the HTML and XHTML specifications and therefore produces the same DOM tree whether parsed as HTML or XML is known as polyglot markup.
There is no DTD for XHTML5.
HTML5 is designed so that old browsers can safely ignore new HTML5 constructs. In contrast to HTML 4.01, the HTML5 specification gives detailed rules for lexing and parsing, with the intent that compliant browsers will produce the same results when parsing incorrect syntax. Although HTML5 now defines a consistent behavior for "tag soup" documents, those documents do not conform to the HTML5 standard.
According to a report released on 30 September 2011, 34 of the world's top 100 Web sites were using HTML5 – the adoption led by search engines and social networks. Another report released in August 2013 has shown that 153 of the Fortune 500 U.S. companies implemented HTML5 on their corporate websites.
Since 2014, HTML5 is at least partially supported by most popular layout engines.
Differences from HTML 4.01 and XHTML 1.xEdit
The following is a cursory list of differences and some specific examples.
- New parsing rules: oriented towards flexible parsing and compatibility; not based on SGML
- Ability to use inline SVG and MathML in
- New elements:
- New types of form controls:
dates and times,
- New attributes:
- Global attributes (that can be applied for every element):
data-*(custom data attributes)
- Deprecated elements will be dropped altogether:
W3C Working Group publishes "HTML5 differences from HTML 4", which provides a complete outline of additions, removals and changes between HTML5 and HTML4.
On 18 January 2011, the W3C introduced a logo to represent the use of or interest in HTML5. Unlike other badges previously issued by the W3C, it does not imply validity or conformance to a certain standard. As of 1 April 2011, this logo is official.
When initially presenting it to the public, the W3C announced the HTML5 logo as a "general-purpose visual identity for a broad set of open web technologies, including HTML5, CSS, SVG, WOFF, and others". Some web standard advocates, including The Web Standards Project, criticized that definition of "HTML5" as an umbrella term, pointing out the blurring of terminology and the potential for miscommunication. Three days later, the W3C responded to community feedback and changed the logo's definition, dropping the enumeration of related technologies. The W3C then said the logo "represents HTML5, the cornerstone for modern Web applications".
Digital rights managementEdit
This section needs to be updated. The reason given is: EME is now a W3C recommendation and thus this section seems outdated.(June 2019)
Industry players including the BBC, Google, Microsoft, Apple Inc. have been lobbying for the inclusion of Encrypted Media Extensions (EME), a form of digital rights management (DRM), into the HTML5 standard. As of the end of 2012 and the beginning of 2013, 27 organizations including the Free Software Foundation have started a campaign against including digital rights management in the HTML5 standard. However, in late September 2013, the W3C HTML Working Group decided that Encrypted Media Extensions, a form of DRM, was "in scope" and will potentially be included in the HTML5.1 standard. WHATWG's "HTML Living Standard" continued to be developed without DRM-enabled proposals.
Manu Sporny, a member of the W3C, said that EME would not solve the problem it was supposed to address. Opponents point out that EME itself is just an architecture for a DRM plug-in mechanism.
The initial enablers for DRM in HTML5 were Google and Microsoft. Supporters also include Adobe. On 14 May 2014, Mozilla announced plans to support EME in Firefox, the last major browser to avoid DRM. Calling it "a difficult and uncomfortable step", Andreas Gal of Mozilla explained that future versions of Firefox would remain open source but ship with a sandbox designed to run a content decryption module developed by Adobe, later it was replaced with Widevine module from Google which is much more widely adopted by content providers. While promising to "work on alternative solutions", Mozilla's Executive Chair Mitchell Baker stated that a refusal to implement EME would have accomplished little more than convincing many users to switch browsers. This decision was condemned by Cory Doctorow and the Free Software Foundation.
- "Mac Developer Library: System-Declared Uniform Type Identifiers". Apple. 17 November 2009.
- "HTML5: A vocabulary and associated APIs for HTML and XHTML". W3.org. W3C. 22 January 2008. Retrieved 28 January 2009.
- Cimpanu, Catalin (29 May 2019). "Browser vendors Win War with W3C over HTML and DOM standards". ZDNet. Archived from the original on 29 May 2019. Retrieved 29 May 2019.
- "HTML5 specification finalized, squabbling over specs continues". Ars Technica. 29 October 2014. Retrieved 29 October 2014.
- "HTML5 is a W3C recommendation". W3C Blog. World Wide Web Consortium (W3C). 28 October 2014. Retrieved 28 October 2014.
- "HTML5 Differences from HTML4". W3.org. W3C. Introduction. Retrieved 2 March 2018.
- "HTML5 Differences from HTML4". W3.org. W3C. 19 October 2010. Retrieved 4 December 2010.
- "HTML 5.2 W3C Recommendation". W3.org. W3C. 14 December 2017. § 1.10.2 Syntax Errors. Retrieved 29 June 2017.
- "HTML 4 Errata". World Wide Web Consortium. Retrieved 4 December 2010.
- "HTML 5.2 W3C Recommendation". W3.org. W3C. 14 December 2017. § 1.4 History. Retrieved 9 August 2017.
- "Position Paper for the W3C Workshop on Web Applications and Compound Documents". W3.org. W3C. Retrieved 30 December 2011.
- "W3C Workshop on Web Applications and Compound Documents (Day 1)". W3.org. W3C. 1 June 2004. Retrieved 30 December 2011.
- "W3C Workshop on Web Applications and Compound Documents (Day 2)". W3.org. W3C. 2 June 2004. Retrieved 30 December 2011.
- Hickson, -Ian (5 June 2004). "[whatwg] WHAT open mailing list announcement". Lists.W3.org. W3C. Retrieved 8 December 2015.
- Pilgrim, Mark (15 September 2008). "This Week in HTML 5 – Episode 5". WHATWG Blog. WHATWG. Retrieved 30 December 2011.
- "FOX News: No Flash on the iPhone? Apple's Steve Jobs Finally Explains Why". Fox News Channel. 29 April 2010.
- "TIME: Steve Jobs: 'Flash is No Longer Necessary' and Other Musings". Time. 29 April 2010.
- "Steve Jobs: Why Apple Banned Flash". CBS News.
- "FastCompany: Steve Jobs: Adobe's Flash Is Old PC History, Open Web Is the Future". 29 April 2010.
- "'Thoughts on Flash', by Steve Jobs, CEO of Apple, Inc". Apple.com. Retrieved 8 January 2014.
- "Is HTML5 Replacing Flash?". Lyquix.com. Retrieved 8 January 2014.
- "Flash to Focus on PC Browsing and Mobile Apps; Adobe to More Aggressively Contribute to HTML5". adobe.com. Retrieved 26 February 2012.
- Warren, Tom (25 July 2017). "Adobe will finally kill Flash in 2020". The Verge.
- Lotus, Jean (1 January 2021). "Adobe Flash reaches end of life with nostalgia from users". UPI.
- "W3C Confirms May 2011 for HTML5 Last Call, Targets 2014 for HTML5 Standard". World Wide Web Consortium. 14 February 2011. Retrieved 18 February 2011.
- Hickson, Ian. "HTML Is the New HTML5". Archived from the original on 6 October 2019. Retrieved 21 January 2011.
- "HTML5 gets the splits". NetMagazine.com. Retrieved 23 July 2012.
- "HTML5". W3.org. 17 December 2012. Retrieved 15 June 2013.
- "When Will HTML5 Be Finished?". FAQ. WHAT Working Group. Retrieved 29 November 2009.
- "Call for Review: HTML5 Proposed Recommendation Published W3C News". W3.org. W3C. 16 September 2014. Retrieved 27 September 2014.
- "Open Web Platform Milestone Achieved with HTML5 Recommendation". W3.org. W3C. 28 October 2014. Retrieved 29 October 2014.
- "HTML 5.1 W3C Recommendation". W3.org. W3C. Retrieved 26 February 2017.
- "HTML 5.2 W3C Recommendation". W3.org. W3C. Retrieved 14 December 2017.
- "HTML5 Publication History - W3C".
- "HTML 3.2 Reference Specification Publication History - W3C".
- "HTML 4.0 Publication History - W3C".
- "HTML 4.01 Publication History - W3C".
- "XHTML™ 1.0 The Extensible HyperText Markup Language (Second Edition) Publication History - W3C".
- "XHTML™ 1.1 - Module-based XHTML - Second Edition Publication History - W3C".
- "HTML 5.2 Publication History - W3C".
- "HTML 5.3 Publication History - W3C".
- "Web Applications 1.0". 3 May 2007. Archived from the original on 3 May 2007. Retrieved 18 September 2018.
- "HTML5 Publication History - W3C".
- "HTML 5.1 2nd Edition Publication History - W3C".
- "Plan 2014". World Wide Web Consortium. Retrieved 23 September 2012.
- "HTML 5.2 Publication History - W3C".
- "HTML5.3". World Wide Web Consortium. 14 December 2017. W3C First Public Working Draft.
- "HTML 5.3 Publication History - W3C".
- Jaffe, Jeff (28 May 2019). "W3C and WHATWG to Work Together to Advance the Open Web Platform". W3C Blog. Archived from the original on 29 May 2019. Retrieved 29 May 2019.
- "W3C and the WHATWG Signed an Agreement to Collaborate on a Single Version of HTML and DOM". W3C. 28 May 2019. Archived from the original on 29 May 2019. Retrieved 29 May 2019.
- "Memorandum of Understanding Between W3C and WHATWG". W3C. 28 May 2019. Archived from the original on 29 May 2019. Retrieved 29 May 2019.
- Hoffmann, Jay (2017). "A Tale of Two Standards". The History of the Web. Archived from the original on 1 September 2017. Retrieved 26 January 2018. (Original title: "When Standards Divide".)
- "HTML 5.2 W3C Recommendation". W3.org. W3C. 14 December 2017. § 4.5.6. The cite element. Retrieved 26 July 2018.
- "HTML Living Standard". HTML.spec.WHATWG.org. WHATWG. 25 July 2018. § 4.5.6 The cite element. Retrieved 26 July 2018.
- "HTML Living Standard". HTML.spec.WHATWG.org. WHATWG. 25 July 2018. § 1 Introduction; §1.6 History. Retrieved 26 July 2018.
- "W3C and the WHATWG Signed an Agreement to Collaborate on a Single Version of HTML and DOM". W3C. 28 May 2019. Retrieved 29 May 2019.
- "HTML 5.2". w3.org. Retrieved 18 September 2018.
- "HTML Standard". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML Standard, One-Page Version". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML Standard, Chapter 5: Microdata". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, Chapter 9: Communication". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, Chapter 10: Web workers". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, Chapter 11: Web storage". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML 5.2, § 3.2.5. Global attributes". w3.org. Retrieved 18 September 2018.
- "HTML Standard, § 3.2.6 Global attributes". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML Standard, § 4.13 Custom elements". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML 5.2: § 4.5.11. The rb element". w3.org. Retrieved 19 September 2018.
- "HTML 5.2: § 4.5.13. The rtc element". w3.org. Retrieved 19 September 2018.
- "HTML 5.2: § 4.4.2. The address element". w3.org. Retrieved 19 September 2018.
- "HTML Standard, § 4.3.7 The hgroup element". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, § 4.4.7 The menu element". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, § 4.12.4 The slot element". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, § 4.3.10 The address element". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML 5.2: § 184.108.40.206. Other pragma directives". w3.org. Retrieved 19 September 2018.
- "PragmaExtensions – WHATWG Wiki". wiki.whatwg.org. Retrieved 19 September 2018.
This document is obsolete.
- "HTML Standard, § 220.127.116.11 Sample outlines". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML Standard, § 18.104.22.168 Exposing outlines to users". html.spec.whatwg.org. Retrieved 19 September 2018.
- "HTML 5.2: § 4.3.2. The article element". w3.org. Retrieved 18 September 2018.
- "HTML 5.2: § 4.5.16. The time element". w3.org. Retrieved 18 September 2018.
- "HTML+RDFa 1.1 – Second Edition". w3.org. Retrieved 18 September 2018.
- "RDFa Lite 1.1 – Second Edition". w3.org. Retrieved 18 September 2018.
- "HTML Standard, § 4.3.2 The article element". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML Standard, § 4.3.4 The nav element". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML Standard, § 4.4.9 The dl element". html.spec.whatwg.org. Retrieved 18 September 2018.
- "HTML Standard, § 4.5.14 The time element". html.spec.whatwg.org. Retrieved 18 September 2018.
- "<rb>: The Ruby Base element". MDN Web Docs. Retrieved 19 September 2018.
- "<rtc>: The Ruby Text Container element". MDN Web Docs. Retrieved 19 September 2018.
- "<hgroup>". MDN Web Docs. Retrieved 19 September 2018.
- "<menu>". MDN Web Docs. Retrieved 19 September 2018.
- "<slot>". MDN Web Docs. Retrieved 19 September 2018.
- "PubStatus – WEBAPPS". W3.org. W3C.
- Introduction to HTML 5 video
- IBM Developer Works New elements in HTML5: Structure and semantics
- ICAMD.org Finalcut Silverlight Films that Videographers share Quicktime in a Flash: Video on the Web using HTML5 and other Codecs
- "11 Obsolete features – HTML5". W3C. Retrieved 11 March 2014.
- HTML5 DTD: "HTML5 is not SGML-based, and there will be no official DTD for it."
- HTML 5 Reference: "Although it is inspired by its SGML origins, in practice, it really only shares minor syntactic similarities. ... As HTML5 is no longer formally based upon SGML, the DOCTYPE no longer serves this purpose, and thus no longer needs to refer to a DTD."
- Suetos, Shannon (26 April 2010). "HTML5: Worth the Hype?". instantshift.com. Retrieved 21 October 2012.
- "Web Forms 2.0". 5 January 2009. Retrieved 11 February 2014. obsolescence notice
- "HTML". whatwg.org.
- Sergey Mavrody, Sergey's HTML5 & CSS3 Quick Reference, 2nd ed. Belisso Corp., 2012. ISBN 978-0-9833867-2-8
- van Kesteren, Anne; Pieters, Simon. "HTML5 differences from HTML4". World Wide Web Consortium. Retrieved 29 June 2017.
- "Get Started with HTM Canvas". syntaxxx.com. Archived from the original on 18 October 2014. Retrieved 13 October 2014.
- "HTML". whatwg.org.
- "Offline Web Applications". World Wide Web Consortium.
- "HTML". whatwg.org.
- "HTML". whatwg.org.
- "The History interface". w3.org.
- "HTML". whatwg.org.
- "HTML". whatwg.org.
- "HTML". whatwg.org.
- "Web Messaging specification". whatwg.org.
- "Web Storage specification". whatwg.org.
- "1 Introduction – HTML Standard". Whatwg.org. Retrieved 8 January 2014.
- "Indexed Database". World Wide Web Consortium.
- "File API". W3.org. Retrieved 8 January 2014.
- "File API". World Wide Web Consortium.
- "Filesystem API". World Wide Web Consortium.
- "File API: Writer". World Wide Web Consortium.
- "Web Audio API". World Wide Web Consortium. Retrieved 2 March 2018.
- MDN. "element.classList".
- "Web Cryptography API". w3.org.
- "WebRTC 1.0: Real-time Communication Between Browsers". w3.org. Archived from the original on 7 April 2019. Retrieved 17 June 2016.
- "Web SQL Database". World Wide Web Consortium.
- Williamson, James (2010). "What HTML5 is (and what it isn't)". Retrieved 14 May 2014.
- Graff, Eliot. "Polyglot Markup: HTML-Compatible XHTML Documents". W3C. Retrieved 6 July 2013.
- "14 The XML syntax". HTML Standard. WHATWG.
- "FAQ – WHATWG Wiki". WHATWG. Retrieved 26 August 2011.
- "Percentage of Web sites Using HTML5". binvisions. 30 September 2011. Retrieved 21 October 2011.
- "HTML5 Popularity Among Fortune 500 Companies". INCORE. Retrieved 5 March 2013.
- "HTML5 form additions". World Wide Web Consortium. Retrieved 13 October 2014.
- "HTML5 Differences from HTML4". FAQ. World Wide Web Consortium. 9 December 2014. Retrieved 2 March 2018.
- "W3C HTML5 Logo FAQ". World Wide Web Consortium. Retrieved 21 January 2011.
Is this W3C's "official" logo for HTML5? Yes, as of 1 April 2011.
- "HTML5 Logo: Be Proud, But Don't Muddy the Waters!". The Web Standards Project. Archived from the original on 10 August 2011. Retrieved 22 January 2011.
- "The HTML5 Logo Conversation". World Wide Web Consortium. Retrieved 21 January 2011.
- Encrypted Media Extensions draft specification of the W3C
- Bright, Peter (16 April 2013). "Netflix coming to HTML5 just as soon as the DRM ducks are in a row". Ars Technica.
- Sporny, Manu (26 January 2013). "DRM in HTML5".
- "Tell W3C: We don't want the Hollyweb". Free Software Foundation. May 2013.
- "HTML5 webpage locks 'would stifle innovation'". BBC News. 30 May 2013.
- "Une coalition de vingt-sept organisations demande au W3C de garder les menottes numériques (DRM) hors des standards du Web". 24 April 2013. Retrieved 14 May 2014.
- "Tell W3C: We don't want the Hollyweb – Free Software Foundation". defectivebydesign.org. Archived from the original on 3 April 2013. Retrieved 6 May 2013.
- Stallman, Richard (2 May 2013). "The W3C's Soul at Stake". The Free Software Foundation. Retrieved 14 May 2014.
- Lord, Timothy (16 April 2013). "Netflix Wants to Go HTML5, but Not Without DRM". Retrieved 14 May 2014.
- "New Charter for the HTML Working Group from Philippe Le Hegaret on 2013-09-30 (email@example.com from September 2013)". Lists.w3.org. 30 September 2013. Retrieved 8 January 2014.
- O'Brien, Danny (2 October 2013). "Lowering Your Standards: DRM and the Future of the W3C". Electronic Frontier Foundation. Retrieved 3 October 2013.
- Sporny, Manu (26 January 2013). "DRM in HTML5". The Beautiful, Tormented Machine. Manu Sporny. Archived from the original on 25 April 2014. Retrieved 16 May 2014.
- Gilbertson, Scott (12 February 2013). "DRM for the Web? Say It Ain't So". Webmonkey. Archived from the original on 24 March 2013. Retrieved 21 March 2013.
- "Releasenotes for Google Chrome 25.0.1364.87".
- "HTML5 Video in IE 11 on Windows 8.1". 18 April 2017.
- Adobe Support for Encrypted Media Extensions Adobe.com. 19 June 2013.
- Gal, Andreas (14 May 2014). "Reconciling Mozilla's Mission and W3C EME". Mozilla. Retrieved 20 May 2014.
- Baker, Mitchell (14 May 2014). "DRM and the Challenge of Serving Users". Mozilla. Retrieved 20 May 2014.
- Doctorow, Cory (14 May 2014). "Firefox's adoption of closed-source DRM breaks my heart". The Guardian. Retrieved 20 May 2014.
- "FSF condemns partnership between Mozilla and Adobe to support Digital Rights Management". Free Software Foundation. 14 May 2014. Retrieved 20 May 2014.
- HTML Living standard from WHATWG, GitHub repo
- WHATWG validator of latest HTML Living standard
- W3C TRs, HTML5.3 is deprecated in favour of WHATWG HTML Living standard
- Memorandum of Understanding Between W3C and WHATWG
- HTML Media Extensions Working Group
- HTML.next, Feature requests for future versions of HTML