HTML 5

Abstract

This specification introduces features to HTML and the DOM that ease the authoring of Web-based applications. Additions include the context menus, a direct-mode graphics canvas, inline popup windows, and server-sent events.

Status of this document

This is a work in progress! This document is changing on a daily if not hourly basis in response to comments and as a general part of its development process. Comments are very welcome, please send them to whatwg@whatwg.org. Thank you.

Implementors should be aware that this specification is not stable. Implementors who are not taking part in the discussions are likely to find the specification changing out from under them in incompatible ways. Vendors interested in implementing this specification before it eventually reaches the call for implementations should join the WHATWG mailing list and take part in the discussions.

This specification is also being produced by the W3C HTML WG. The two specifications are identical from the table of contents onwards.

This specification is intended to replace (be the new version of) what was previously the HTML4, XHTML 1.x, and DOM2 HTML specifications.

Stability

Different parts of this specification are at different levels of maturity.

Some of the more major known issues are marked like this. There are many other issues that have been raised as well; the issues given in this document are not the only known issues! There are also some spec-wide issues that have not yet been addressed: case-sensitivity is a very poorly handled topic right now, and the firing of events needs to be unified (right now some bubble, some don't, they all use different text to fire events, etc).

Table of contents

• 1. Introduction
  • 1.1. Scope
    • 1.1.1. Relationship to HTML 4.01, XHTML 1.1, DOM2 HTML
    • 1.1.2. Relationship to XHTML2
    • 1.1.3. Relationship to XUL, Flash, Silverlight, and other proprietary UI languages
  • 1.2. Structure of this specification
    • 1.2.1. How to read this specification
  • 1.3. Conformance requirements
    • 1.3.1. Common conformance requirements for APIs exposed to JavaScript
    • 1.3.2. Dependencies
    • 1.3.3. Features defined in other specifications
  • 1.4. Terminology
    • 1.4.1. HTML vs XHTML
• 2. The Document Object Model
  • 2.1. Documents
    • 2.1.1. Security
    • 2.1.2. Resource metadata management
  • 2.2. Elements
    • 2.2.1. Reflecting content attributes in DOM attributes
  • 2.3. Common DOM interfaces
    • 2.3.1. Collections
      • 2.3.1.1. HTMLCollection
      • 2.3.1.2. HTMLFormControlsCollection
      • 2.3.1.3. HTMLOptionsCollection
    • 2.3.2. DOMTokenList
    • 2.3.3. DOM feature strings
  • 2.4. DOM tree accessors
  • 2.5. Dynamic markup insertion
    • 2.5.1. Controlling the input stream
    • 2.5.2. Dynamic markup insertion in HTML
    • 2.5.3. Dynamic markup insertion in XML
  • 2.6. APIs in HTML documents
• 3. Semantics and structure of HTML elements
  • 3.1. Introduction
  • 3.2. Common microsyntaxes
    • 3.2.1. Common parser idioms
    • 3.2.2. Boolean attributes
    • 3.2.3. Numbers
      • 3.2.3.1. Unsigned integers
      • 3.2.3.2. Signed integers
      • 3.2.3.3. Real numbers
      • 3.2.3.4. Ratios
      • 3.2.3.5. Percentages and dimensions
      • 3.2.3.6. Lists of integers
    • 3.2.4. Dates and times
      • 3.2.4.1. Specific moments in time
      • 3.2.4.2. Vaguer moments in time
    • 3.2.5. Time offsets
    • 3.2.6. Tokens
    • 3.2.7. Keywords and enumerated attributes
    • 3.2.8. References
  • 3.3. Documents and document fragments
    • 3.3.1. Semantics
    • 3.3.2. Structure
    • 3.3.3. Kinds of elements
      • 3.3.3.1. Block-level elements
      • 3.3.3.2. Inline-level content
      • 3.3.3.3. Transparent content models
      • 3.3.3.4. Determining if a particular element contains block-level elements or inline-level content
      • 3.3.3.5. Interactive elements
      • 3.3.3.6. Paragraphs
  • 3.4. Global attributes
    • 3.4.1. The id attribute
    • 3.4.2. The title attribute
    • 3.4.3. The lang (HTML only) and xml:lang (XML only) attributes
    • 3.4.4. The dir attribute
    • 3.4.5. The class attribute
    • 3.4.6. The irrelevant attribute
  • 3.5. Interaction
    • 3.5.1. Activation
    • 3.5.2. Focus
      • 3.5.2.1. Focus management
      • 3.5.2.2. Sequential focus navigation
    • 3.5.3. Scrolling elements into view
  • 3.6. The root element
    • 3.6.1. The html element
  • 3.7. Document metadata
    • 3.7.1. The head element
    • 3.7.2. The title element
    • 3.7.3. The base element
    • 3.7.4. The link element
    • 3.7.5. The meta element
      • 3.7.5.1. Standard metadata names
      • 3.7.5.2. Other metadata names
      • 3.7.5.3. Pragma directives
      • 3.7.5.4. Specifying the document's character encoding
    • 3.7.6. The style element
    • 3.7.7. Styling
  • 3.8. Sections
    • 3.8.1. The body element
    • 3.8.2. The section element
    • 3.8.3. The nav element
    • 3.8.4. The article element
    • 3.8.5. The blockquote element
    • 3.8.6. The aside element
    • 3.8.7. The h1, h2, h3, h4, h5, and h6 elements
    • 3.8.8. The header element
    • 3.8.9. The footer element
    • 3.8.10. The address element
    • 3.8.11. Headings and sections
      • 3.8.11.1. Creating an outline
      • 3.8.11.2. Determining which heading and section applies to a particular node
      • 3.8.11.3. Distinguishing site-wide headers from page headers
  • 3.9. Prose
    • 3.9.1. The p element
    • 3.9.2. The hr element
    • 3.9.3. The br element
    • 3.9.4. The dialog element
  • 3.10. Preformatted text
    • 3.10.1. The pre element
  • 3.11. Lists
    • 3.11.1. The ol element
    • 3.11.2. The ul element
    • 3.11.3. The li element
    • 3.11.4. The dl element
    • 3.11.5. The dt element
    • 3.11.6. The dd element
  • 3.12. Phrase elements
    • 3.12.1. The a element
    • 3.12.2. The q element
    • 3.12.3. The cite element
    • 3.12.4. The em element
    • 3.12.5. The strong element
    • 3.12.6. The small element
    • 3.12.7. The m element
    • 3.12.8. The dfn element
    • 3.12.9. The abbr element
    • 3.12.10. The time element
    • 3.12.11. The meter element
    • 3.12.12. The progress element
    • 3.12.13. The code element
    • 3.12.14. The var element
    • 3.12.15. The samp element
    • 3.12.16. The kbd element
    • 3.12.17. The sup and sub elements
    • 3.12.18. The span element
    • 3.12.19. The i element
    • 3.12.20. The b element
    • 3.12.21. The bdo element
  • 3.13. Edits
    • 3.13.1. The ins element
    • 3.13.2. The del element
    • 3.13.3. Attributes common to ins and del elements
  • 3.14. Embedded content
    • 3.14.1. The figure element
    • 3.14.2. The img element
    • 3.14.3. The iframe element
    • 3.14.4. The embed element
    • 3.14.5. The object element
    • 3.14.6. The param element
    • 3.14.7. The video element
      • 3.14.7.1. Video and audio codecs for video elements
    • 3.14.8. The audio element
      • 3.14.8.1. Audio codecs for audio elements
    • 3.14.9. Media elements
      • 3.14.9.1. Error codes
      • 3.14.9.2. Location of the media resource
      • 3.14.9.3. Network states
      • 3.14.9.4. Loading the media resource
      • 3.14.9.5. Offsets into the media resource
      • 3.14.9.6. The ready states
      • 3.14.9.7. Playing the media resource
      • 3.14.9.8. Seeking
      • 3.14.9.9. Cue points
      • 3.14.9.10. User interface
      • 3.14.9.11. Time range
      • 3.14.9.12. Event summary
      • 3.14.9.13. Security and privacy considerations
    • 3.14.10. The source element
    • 3.14.11. The canvas element
      • 3.14.11.1. The 2D context
        • 3.14.11.1.1. The canvas state
        • 3.14.11.1.2. Transformations
        • 3.14.11.1.3. Compositing
        • 3.14.11.1.4. Colors and styles
        • 3.14.11.1.5. Line styles
        • 3.14.11.1.6. Shadows
        • 3.14.11.1.7. Simple shapes (rectangles)
        • 3.14.11.1.8. Complex shapes (paths)
        • 3.14.11.1.9. Images
        • 3.14.11.1.10. Pixel manipulation
        • 3.14.11.1.11. Drawing model
    • 3.14.12. The map element
    • 3.14.13. The area element
    • 3.14.14. Image maps
  • 3.15. Tabular data
    • 3.15.1. The table element
    • 3.15.2. The caption element
    • 3.15.3. The colgroup element
    • 3.15.4. The col element
    • 3.15.5. The tbody element
    • 3.15.6. The thead element
    • 3.15.7. The tfoot element
    • 3.15.8. The tr element
    • 3.15.9. The td element
    • 3.15.10. The th element
    • 3.15.11. Processing model
      • 3.15.11.1. Forming a table
      • 3.15.11.2. Forming relationships between data cells and header cells
  • 3.16. Forms
    • 3.16.1. The form element
    • 3.16.2. The fieldset element
    • 3.16.3. The input element
    • 3.16.4. The button element
    • 3.16.5. The label element
    • 3.16.6. The select element
    • 3.16.7. The datalist element
    • 3.16.8. The optgroup element
    • 3.16.9. The option element
    • 3.16.10. The textarea element
    • 3.16.11. The output element
    • 3.16.12. Processing model
      • 3.16.12.1. Form submission
  • 3.17. Scripting
    • 3.17.1. The script element
      • 3.17.1.1. Scripting languages
    • 3.17.2. The noscript element
    • 3.17.3. The event-source element
  • 3.18. Interactive elements
    • 3.18.1. The details element
    • 3.18.2. The datagrid element
      • 3.18.2.1. The datagrid data model
      • 3.18.2.2. How rows are identified
      • 3.18.2.3. The data provider interface
      • 3.18.2.4. The default data provider
        • 3.18.2.4.1. Common default data provider method definitions for cells
      • 3.18.2.5. Populating the datagrid element
      • 3.18.2.6. Updating the datagrid
      • 3.18.2.7. Requirements for interactive user agents
      • 3.18.2.8. The selection
      • 3.18.2.9. Columns and captions
    • 3.18.3. The command element
    • 3.18.4. The menu element
      • 3.18.4.1. Introduction
      • 3.18.4.2. Building menus and tool bars
      • 3.18.4.3. Context menus
      • 3.18.4.4. Toolbars
    • 3.18.5. Commands
      • 3.18.5.1. Using the a element to define a command
      • 3.18.5.2. Using the button element to define a command
      • 3.18.5.3. Using the input element to define a command
      • 3.18.5.4. Using the option element to define a command
      • 3.18.5.5. Using the command element to define a command
  • 3.19. Data Templates
    • 3.19.1. The datatemplate element
    • 3.19.2. The rule element
    • 3.19.3. The nest element
    • 3.19.4. Processing model
  • 3.20. Miscellaneous elements
    • 3.20.1. The legend element
    • 3.20.2. The div element
• 4. Web browsers
  • 4.1. Browsing contexts
    • 4.1.1. Nested browsing contexts
    • 4.1.2. Auxiliary browsing contexts
    • 4.1.3. Secondary browsing contexts
    • 4.1.4. Threads
    • 4.1.5. Browsing context names
  • 4.2. The default view
    • 4.2.1. Security
    • 4.2.2. Constructors
    • 4.2.3. APIs for creating and navigating browsing contexts by name
    • 4.2.4. Accessing other browsing contexts
  • 4.3. Session history and navigation
    • 4.3.1. The session history of browsing contexts
    • 4.3.2. The History interface
    • 4.3.3. Activating state objects
    • 4.3.4. The Location interface
      • 4.3.4.1. Security
    • 4.3.5. Implementation notes for session history
  • 4.4. Links
    • 4.4.1. Hyperlink elements
    • 4.4.2. Following hyperlinks
      • 4.4.2.1. Hyperlink auditing
    • 4.4.3. Link types
      • 4.4.3.1. Link type "alternate"
      • 4.4.3.2. Link type "archives"
      • 4.4.3.3. Link type "author"
      • 4.4.3.4. Link type "bookmark"
      • 4.4.3.5. Link type "contact"
      • 4.4.3.6. Link type "external"
      • 4.4.3.7. Link type "feed"
      • 4.4.3.8. Link type "help"
      • 4.4.3.9. Link type "icon"
      • 4.4.3.10. Link type "license"
      • 4.4.3.11. Link type "nofollow"
      • 4.4.3.12. Link type "pingback"
      • 4.4.3.13. Link type "prefetch"
      • 4.4.3.14. Link type "search"
      • 4.4.3.15. Link type "stylesheet"
      • 4.4.3.16. Link type "sidebar"
      • 4.4.3.17. Link type "tag"
      • 4.4.3.18. Hierarchical link types
        • 4.4.3.18.1. Link type "first"
        • 4.4.3.18.2. Link type "index"
        • 4.4.3.18.3. Link type "last"
        • 4.4.3.18.4. Link type "next"
        • 4.4.3.18.5. Link type "prev"
        • 4.4.3.18.6. Link type "up"
      • 4.4.3.19. Other link types
  • 4.5. Interfaces for URI manipulation
  • 4.6. Navigating across documents
    • 4.6.1. Page load processing model for HTML files
    • 4.6.2. Page load processing model for XML files
    • 4.6.3. Page load processing model for text files
    • 4.6.4. Page load processing model for images
    • 4.6.5. Page load processing model for content that uses plugins
    • 4.6.6. Page load processing model for inline content that doesn't have a DOM
    • 4.6.7. Scrolling to a fragment identifier
  • 4.7. Determining the type of a new resource in a browsing context
    • 4.7.1. Content-Type sniffing: text or binary
    • 4.7.2. Content-Type sniffing: unknown type
    • 4.7.3. Content-Type sniffing: image
    • 4.7.4. Content-Type sniffing: feed or HTML
    • 4.7.5. Content-Type metadata
  • 4.8. User prompts
  • 4.9. Scripting
    • 4.9.1. Running executable code
    • 4.9.2. Origin
    • 4.9.3. Security exceptions
    • 4.9.4. The javascript: protocol
    • 4.9.5. Events
      • 4.9.5.1. Event handler attributes
      • 4.9.5.2. Event firing
      • 4.9.5.3. Events and the Window object
      • 4.9.5.4. Runtime script errors
  • 4.10. Browser state
    • 4.10.1. Offline Web applications
    • 4.10.2. Custom protocol and content handlers
      • 4.10.2.1. Security and privacy
      • 4.10.2.2. Sample user interface
  • 4.11. Client-side session and persistent storage of name/value pairs
    • 4.11.1. Introduction
    • 4.11.2. The Storage interface
    • 4.11.3. The StorageItem interface
    • 4.11.4. The sessionStorage attribute
    • 4.11.5. The globalStorage attribute
    • 4.11.6. The storage event
    • 4.11.7. Miscellaneous implementation requirements for storage areas
      • 4.11.7.1. Disk space
      • 4.11.7.2. Threads
    • 4.11.8. Security and privacy
      • 4.11.8.1. User tracking
      • 4.11.8.2. Cookie resurrection
      • 4.11.8.3. Integrity of "public" storage areas
      • 4.11.8.4. Cross-protocol and cross-port attacks
      • 4.11.8.5. DNS spoofing attacks
      • 4.11.8.6. Cross-directory attacks
      • 4.11.8.7. Public storage areas corresponding to hosts
      • 4.11.8.8. Storage areas in the face of untrusted higher-level domains that do not correspond to public storage areas
      • 4.11.8.9. Storage areas in the face of untrusted subdomains
      • 4.11.8.10. Implementation risks
  • 4.12. Client-side database storage
    • 4.12.1. Introduction
    • 4.12.2. Executing SQL statements
    • 4.12.3. Database query results
    • 4.12.4. Privacy
    • 4.12.5. Security
      • 4.12.5.1. User agents
      • 4.12.5.2. SQL injection
• 5. Editing
  • 5.1. Introduction
  • 5.2. The contenteditable attribute
    • 5.2.1. User editing actions
    • 5.2.2. Making entire documents editable
  • 5.3. Drag and drop
    • 5.3.1. The DragEvent and DataTransfer interfaces
    • 5.3.2. Events fired during a drag-and-drop action
    • 5.3.3. Drag-and-drop processing model
      • 5.3.3.1. When the drag-and-drop operation starts or ends in another document
      • 5.3.3.2. When the drag-and-drop operation starts or ends in another application
    • 5.3.4. The draggable attribute
    • 5.3.5. Copy and paste
      • 5.3.5.1. Copy to clipboard
      • 5.3.5.2. Cut to clipboard
      • 5.3.5.3. Paste from clipboard
      • 5.3.5.4. Paste from selection
    • 5.3.6. Security risks in the drag-and-drop model
  • 5.4. Undo history
    • 5.4.1. The UndoManager interface
    • 5.4.2. Undo: moving back in the undo transaction history
    • 5.4.3. Redo: moving forward in the undo transaction history
    • 5.4.4. The UndoManagerEvent interface and the undo and redo events
    • 5.4.5. Implementation notes
  • 5.5. Command APIs
  • 5.6. The text selection APIs
    • 5.6.1. APIs for the browsing context selection
    • 5.6.2. APIs for the text field selections
• 6. Communication
  • 6.1. Event definitions
  • 6.2. Server-sent DOM events
    • 6.2.1. The RemoteEventTarget interface
    • 6.2.2. Connecting to an event stream
    • 6.2.3. Parsing an event stream
    • 6.2.4. Interpreting an event stream
    • 6.2.5. Notes
  • 6.3. Network connections
    • 6.3.1. Introduction
    • 6.3.2. The Connection interface
    • 6.3.3. Connection Events
    • 6.3.4. TCP connections
    • 6.3.5. Broadcast connections
      • 6.3.5.1. Broadcasting over TCP/IP
      • 6.3.5.2. Broadcasting over Bluetooth
      • 6.3.5.3. Broadcasting over IrDA
    • 6.3.6. Peer-to-peer connections
      • 6.3.6.1. Peer-to-peer connections over TCP/IP
      • 6.3.6.2. Peer-to-peer connections over Bluetooth
      • 6.3.6.3. Peer-to-peer connections over IrDA
    • 6.3.7. The common protocol for TCP-based connections
      • 6.3.7.1. Clients connecting over TCP
      • 6.3.7.2. Servers accepting connections over TCP
      • 6.3.7.3. Sending and receiving data over TCP
    • 6.3.8. Security
    • 6.3.9. Relationship to other standards
  • 6.4. Cross-document messaging
    • 6.4.1. Processing model
• 7. Repetition templates
• 8. The HTML syntax
  • 8.1. Writing HTML documents
    • 8.1.1. The DOCTYPE
    • 8.1.2. Elements
      • 8.1.2.1. Start tags
      • 8.1.2.2. End tags
      • 8.1.2.3. Attributes
      • 8.1.2.4. Optional tags
      • 8.1.2.5. Restrictions on content models
      • 8.1.2.6. Restrictions on the contents of CDATA and RCDATA elements
    • 8.1.3. Text
      • 8.1.3.1. Newlines
    • 8.1.4. Character entity references
    • 8.1.5. Comments
  • 8.2. Parsing HTML documents
    • 8.2.1. Overview of the parsing model
    • 8.2.2. The input stream
      • 8.2.2.1. Determining the character encoding
      • 8.2.2.2. Character encoding requirements
      • 8.2.2.3. Preprocessing the input stream
      • 8.2.2.4. Changing the encoding while parsing
    • 8.2.3. Tokenisation
      • 8.2.3.1. Tokenising entities
    • 8.2.4. Tree construction
      • 8.2.4.1. The initial phase
      • 8.2.4.2. The root element phase
      • 8.2.4.3. The main phase
        • 8.2.4.3.1. The stack of open elements
        • 8.2.4.3.2. The list of active formatting elements
        • 8.2.4.3.3. Creating and inserting HTML elements
        • 8.2.4.3.4. Closing elements that have implied end tags
        • 8.2.4.3.5. The element pointers
        • 8.2.4.3.6. The insertion mode
        • 8.2.4.3.7. How to handle tokens in the main phase
      • 8.2.4.4. The trailing end phase
    • 8.2.5. The End
  • 8.3. Namespaces
  • 8.4. Serialising HTML fragments
  • 8.5. Parsing HTML fragments
  • 8.6. Entities
• 9. WYSIWYG editors
  • 9.1. Presentational markup
    • 9.1.1. WYSIWYG signature
    • 9.1.2. The font element
• 10. Rendering
  • • 10.0.1. Section headers
  • 10.1. Rendering and the DOM
  • 10.2. Rendering and menus/toolbars
    • 10.2.1. The 'icon' property
• 11. Things that you can't do with this specification because they are better handled using other technologies that are further described herein
  • 11.1. Localisation
  • 11.2. Declarative 2D vector graphics and animation
  • 11.3. Declarative 3D scenes
  • 11.4. Timers
  • 11.5. Events
• References
• Acknowledgements