Complementry to HTML 5

HTML5 APIs and related technologies by Sergey Mavrody

HTML5 APIs and Related Technologies: taxonomy and specification status. Illustration by Sergey Mavrody. From Sergey's HTML5 & CSS3 Quick Reference book.

The Web Hypertext Application Technology Working Group is a community of people interested in evolving HTML and related technologies.

WHATWG HTML5 Where does this specification fit?

HTML5 from MDN

"HTML5 is the latest evolution of the standard that defines HTML. The term represents two different concepts. It is a new version of the language HTML, with new elements, attributes, and behaviors, and a larger set of technologies that allows the building of more diverse and powerful Web sites and applications. This set is sometimes called HTML5 & friends and often shortened to just HTML5."

HTML5 Technologies Grouped Based on Function

Icons for the eight high level technology classes (from left to right):
Semantics / Offline & Storage / Device Access / Connectivity / Multimedia / 3d, Graphics & Effects / Performance & Integration /CSS3. Semantics, allowing you to describe more precisely what your content is Offline & Storage, allowing webpages to store data on the client-side locally and operate offline more efficiently.
Device Access, allowing for the usage of various input and output devices. Connectivity, allowing you to communicate with the server in new and innovative ways. Multimedia, making video and audio first-class citizens in the Open Web. 3d, Graphics & Effects,  allowing a much more diverse range of presentation options.
Performance & Integration, providing greater speed optimization and better usage of computer hardware.
Styling,  letting authors write more sophisticated themes.
Icons for the eight high level technology classes (from left to right):
Semantics / Offline & Storage / Device Access / Connectivity / Multimedia / 3d, Graphics & Effects / Performance & Integration /CSS3.

New APIs

Related technologies



The canvas element is part of HTML5 and allows for dynamic, scriptable rendering of 2D shapes and bitmap images.


Version 3 provides many effects including shadows and gradients very useful for improving the appearance of an application. This goes along with the new HTML role which is to serve as interface, but so far, it is not part of HTML 5. Instead we want to completely separate the content and structure of its appearance which is given by CSS.


DOM is the structure of a document and the way to access its elements, it is originally the subject of a separate specification of the W3C and had three main iterations: DOM Level 1, 2 and 3. DOM 4 is being defined. When creating HTML 5, the WHATWG has decided to merge the two standards. It is part of HTML 5 for WHATWG which is concerned only with HTML, but not for the W3C which also defines the XML specification and DOM also supports this format.

Drag and Drop

Editable Content

Encrypted Media Extensions (EME)

A streaming-related effort involves the proposed Encrypted Media Extensions (EME) standard, which extends the HTMLMediaElement (in HTML5.1) to provide APIs for controlling playback of encrypted content and connecting to a digital rights management system. EME provides a standard way of displaying video through browsers.

File API

FileReader and FileWriter are part of the File API spec., not HTML 5, but works in conjunction with XMLHttpRequest (prior to HTML5) and Web Workers as well as the <input> tag. In fact FileWriter is also defined in a separate specification.


This is a different specification even if the API works in web pages. It helps to know the location of customers and thus to provide services based on where they live.



The HTMLTableElement interface provides special properties and methods (beyond the regular HTMLElement object interface it also has available to it by inheritance) for manipulating the layout and presentation of tables in an HTML document.

Indexed DB

It is an API to manage a database on the client from the browser. It succeeds WebDB which was abandoned by the W3C. This is another thing that complements HTML 5, the interface language of Web applications, but is not part of it.

Microdata (HTML)

MIME type

Offline Web Applications



This dialect of XML fits into HTML pages, and is part of the DOM, can be generated and modified in JavaScript. However, it is a separate language and an SVG document can be displayed independently by the browser.

Timed Media Playback


WebGL is a cross-platform, royalty-free web standard for a low-level 3D graphics API based on OpenGL ES, exposed to ECMAScript via the HTML5 Canvas element.


WebRTC is in a W3C specification independent of HTML 5 .WebRTC ("Web Real-Time Communication") is a collection of communications protocols and application programming interfaces that enable real-time communication over peer-to-peer connections. This allows web browsers to not only request resources from backend servers, but also real-time information from browsers of other users.


This protocol of bidirectional access between the browser and the server is standardized by the IETF and has nothing to do with HTML 5. But we tend to use them together, it is ideally suited for applications that work with a local server, among others (it consumes a lot of bandwidth which limits the use of the Web). W3C has a spec for the WebSocket API.

Web Cryptography API

Web SQL Database

  • Web SQL Database Beware. This specification is no longer in active maintenance and the Web Applications Working Group does not intend to maintain it further.

Web Storage

LocalStorage, successor to cookies, can store large amounts of data on the client workstation, so in the browser. As well as sessionStorage, it was initialialement part of HTML 5 and then turned into an independent standard by the W3C.

Web Messaging

Web Workers

A web worker is a JavaScript running in the background, without affecting the performance of the page.