Web standards are the formal, non-proprietary standards and other technical specifications that define and describe aspects of the World Wide Web. In recent years, the term has been more frequently associated with the trend of endorsing a set of standardized best practices for building web sites, and a philosophy of web design and development that includes those methods.
Web standards include many interdependent standards and specifications, some of which govern aspects of the Internet, not just the World Wide Web. Even when not web-focused, such standards directly or indirectly affect the development and administration of web sites and web services. Considerations include the interoperability, accessibility and usability of web pages and web sites.
Web standards consist of the following:
- Recommendations published by the World Wide Web Consortium (W3C), such as HTML/XHTML, Cascading Style Sheets (CSS), image formats such as Portable Network Graphics (PNG) and Scalable Vector Graphics (SVG), as well as accessibility technologies like WAI-ARIA
- Standards and "Living standards" published by the Web Hypertext Application Technology Working Group (WHATWG), such as the HTML Living Standard, DOM Standard, Encoding Standard and URL Standard.
- Standards published by the International Organization for Standardization (ISO), such as JPEG
More broadly, the following technologies may be referred to as "web standards" as well:
- Request for Comments (RFC) documents published by the Internet Engineering Task Force (IETF)
- The Unicode Standard and various Unicode Technical Reports (UTRs) published by the Unicode Consortium
- Name and number registries maintained by the Internet Assigned Numbers Authority (IANA)
Web standards are evolving specifications of web technologies. Web standards are developed by standards organizations—groups of interested and often competing parties chartered with the task of standardization—not technologies developed and declared to be a standard by a single individual or company. It is crucial to distinguish those specifications that are under development from the ones that already reached the final development status (in case of W3C specifications, the highest maturity level).
The web standards movement
The earliest visible manifestation of the web standards movement was the Web Standards Project, launched in August 1998 as a grassroots coalition fighting for improved web standards support in browsers.
The web standards movement supports concepts of standards-based web design, including the separation of document structure from a web page or application's appearance and behavior; an emphasis on semantically structured content that validates (that is, contains no errors of structural composition) when tested against validation software maintained by the World Wide Web Consortium; and progressive enhancement, a layered approach to web page and application creation that enables all people and devices to access the content and functionality of a page, regardless of personal physical ability (accessibility), connection speed, and browser capability.
The Web Standards movement pioneered by Glenn Davis, George Olsen, Jeffrey Zeldman, Steven Champeon, Todd Fahrner, Eric A. Meyer, Tantek Çelik, Dori Smith, Tim Bray, Jeffrey Veen, and other members of the Web Standards Project replaced bandwidth-heavy tag soup with light, semantic markup and progressive enhancement, with the goal of making web content "accessible to all".
In 2007, Douglas Vos initiated the Blue Beanie Day, inspired by Jeffrey Zeldman, who is shown with a blue cap on the book cover of his 2003 book Designing with Web Standards. Since then, the 30 November is the annual international celebration of web standards and web accessibility.
When web standards are discussed, the following publications are typically seen as foundational:
- Recommendations for markup languages, such as Hypertext Markup Language (HTML), Extensible Hypertext Markup Language (XHTML), and Scalable Vector Graphics (SVG) from W3C.
- Recommendations for stylesheets, especially Cascading Style Sheets (CSS), from W3C.
- Recommendations for Document Object Models (DOM), from W3C.
- Properly formed names and addresses for the page and all other resources referenced from it (URIs), based upon RFC 2396, from IETF.
- Proper use of HTTP and MIME to deliver the page, return data from it and to request other resources referenced in it, based on RFC 2616, from IETF.
Work in the W3C toward the Semantic Web is currently focused by publications related to the Resource Description Framework (RDF), Gleaning Resource Descriptions from Dialects of Languages (GRDDL) and Web Ontology Language (OWL).
Standards publications and bodies
A W3C Recommendation is a specification or set of guidelines that, after extensive consensus-building, has received the endorsement of W3C Members and the Director.
An IETF Internet Standard is characterized by a high degree of technical maturity and by a generally held belief that the specified protocol or service provides significant benefit to the Internet community. A specification that reaches the status of Standard is assigned a number in the IETF STD series while retaining its original IETF RFC number.
Non-standard and vendor-proprietary pressures
HTML 5 contains numerous "willful violations" of other specifications, in order to accommodate limitations of existing platforms.
Web Standards Compliance Testing
There are compliance tests both for HTML code generated by websites as well as for the faithful interpretation of HTML code by web browsers.
Compliance tests for website code
W3C offers online services to test websites directly for both web site developers, as well as for website users. These include:
- Markup Validation Service to check the markup (HTML, XHTML, …) of Web documents
- CSS Validation Service to check Cascading Style Sheets (CSS) and (X)HTML documents with style sheets
Compliance tests for web browsers
The Web Standards Project (WaSP), although development is officially inactive, continues to offer two levels of testing services for web browsers:
- "Mission - Web Standards Project". WaSP. Retrieved 2009-01-19.
- "W3C Technical Reports and Publications". W3C. Retrieved 2009-01-19.
- Allsopp, John (2009-12-09). Developing with Web Standards. Berkeley: New Riders. p. 11. ISBN 978-0-321-70271-5.
- "WHATWG Standards". spec.whatwg.org. Retrieved 2020-11-22.
- "Ecma formal publications". Ecma. Retrieved 2009-01-19.,
- "Search for World Wide Web in ISO standards". ISO. Retrieved 2009-01-19.
- "IETF RFC page". IETF. Retrieved 2009-01-19.
- "Unicode Technical Reports". Unicode Consortium. Retrieved 2009-01-19.
- "IANA home page". IANA. Retrieved 2009-01-19.
- Leslie Sikos (2011). Web standards - Mastering HTML5, CSS3, and XML. Apress. ISBN 978-1-4302-4041-9.
- Sliwa, Carol (1998-08-17). "Browser standards targeted". Computerworld. Vol. 32, no. 33. p. 76. ISSN 0010-4841.
- "Web Standards Mission". Archive.webstandards.org. Retrieved 2014-02-26.
- Zeldman, Jeffrey (2008-11-20). "Blue Beanie Day II". Zeldman on Web & Interaction Design. Retrieved 2020-04-21.
- Walker, Alissa (2009-11-30). "Why Is Your Web Designer Wearing a Blue Hat Today?". Fast Company. Retrieved 2020-04-21.
- Berners-Lee, Tim; Fielding, Roy T.; Masinter, Larry (1998). Uniform Resource Identifiers (URI): Generic Syntax. IETF. doi:10.17487/RFC2396. RFC 2396. Retrieved 2009-10-27.
- Fielding, Roy T.; Gettys, James; Mogul, Jeffrey C.; Nielsen, Henrik Frystyk; Masinter, Larry; Leach, Paul J.; Berners-Lee, Tim (1999). Hypertext Transfer Protocol -- HTTP/1.1. IETF. doi:10.17487/RFC2616. RFC 2616. Retrieved 2009-10-27.
- "Web Content Accessibility Guidelines 1.0, W3C Recommendation 5-May-1999". W3C. 1999. Retrieved 2009-02-18.
- "HTML 5 - A vocabulary and associated APIs for HTML and XHTML - Compliance with other specifications". Retrieved 2017-06-29.