Microformats (μF) are a set of defined
HTML classes HTML attributes are special words used inside the opening tag to control the element's behaviour. HTML attributes are a modifier of an '' HTML element type''. An attribute either modifies the default functionality of an element type or provides fu ...
created to serve as consistent and descriptive
metadata Metadata is "data Data (; ) are individual facts, statistics, or items of information, often numeric. In a more technical sense, data are a set of values of qualitative property, qualitative or quantity, quantitative variable (research), v ...

about an
element Element may refer to: Science * Chemical element Image:Simple Periodic Table Chart-blocks.svg, 400px, Periodic table, The periodic table of the chemical elements In chemistry, an element is a pure substance consisting only of atoms that all ...
, designating it as representing a certain type of data (such as contact information,
geographic coordinates Geography (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is ap ...
, events, blog posts, products, recipes, etc.). They allow
software Software is a collection of instructions Instruction or instructions may refer to: Computing * Instruction, one operation of a processor within a computer architecture instruction set * Computer program, a collection of instructions Music * I ...
to process the information reliably by having set classes refer to a specific type of data rather than being arbitrary. Microformats emerged around 2005 and were predominantly designed for use by search engines,
web syndication Web syndication is a form of syndication Syndication may refer to: * Broadcast syndication, where individual stations buy programs outside the network system * Print syndication, where individual newspapers or magazines license news articles, co ...
and aggregators such as
RSS RSS (Resource Description Framework, RDF Site Summary or Really Simple Syndication) is a web feed that allows users and applications to access updates to websites in a Standardization, standardized, computer-readable format. Subscribing to RSS ...

. Although the content of web pages has been capable of some "automated processing" since the inception of the web, such processing is difficult because the markup elements used to display information on the web do not describe what the information means. Microformats can bridge this gap by attaching
semantics Semantics (from grc, σημαντικός ''sēmantikós'', "significant") is the study of reference Reference is a relationship between objects in which one object designates, or acts as a means by which to connect to or link to, another ...
, and thereby obviating other, more complicated, methods of automated processing, such as
natural language processing Natural language processing (NLP) is a subfield of , , and concerned with the interactions between computers and human language, in particular how to program computers to process and analyze large amounts of data. The goal is a computer capab ...
screen scraping Data scraping is a technique where a computer program extracts data from Human-readable medium, human-readable output coming from another program. Description Normally, Data transmission, data transfer between programs is accomplished using data ...

screen scraping
. The use, adoption and processing of microformats enables data items to be indexed, searched for, saved or cross-referenced, so that information can be reused or combined. , microformats allow the encoding and extraction of event details, contact information, social relationships and similar information.


Microformats emerged around 2005 as part of a grassroots movement to make recognizable data items (such as events, contact details or geographical locations) capable of automated processing by software, as well as directly readable by end-users. Link-based microformats emerged first. These include vote links that express opinions of the linked page, which search engines can tally into instant polls.
CommerceNet CommerceNet is a 501(c)6 A 501(c) organization is a nonprofit organization in the Law of the United States#Federal law, federal law of the United States according to Internal Revenue Code and is one of over 29 types of nonprofit organizations exe ...
, a nonprofit organization that promotes
e-commerce E-commerce (electronic commerce) is the activity of electronically buying or selling of Product (business), products on online services or over the Internet. E-commerce draws on technologies such as mobile commerce, electronic funds transfer, su ...

on the Internet, has helped sponsor and promote the technology and support the microformats community in various ways. CommerceNet also helped co-found the Microformats.org community site. Neither CommerceNet nor Microformats.org operates as a
standards body A standards organization, standards body, standards developing organization (SDO), or standards setting organization (SSO) is an organization whose primary function is developing, coordinating, promulgating, revising, amending, reissuing, interpr ...
. The microformats community functions through an open
wiki A wiki ( ) is a hypertext Hypertext is text displayed on a or other with references () to other text that the reader can immediately access. Hypertext documents are interconnected by hyperlinks, which are typically activated b ...

, a mailing list, and an Internet relay chat (
IRC Internet Relay Chat (IRC) is a text-based chat (instant messaging Instant messaging (IM) technology is a type of online chat Online chat may refer to any kind of communication over the Internet that offers a real-time text, real-time t ...
) channel. Most of the existing microformats originated at the Microformats.org wiki and the associated mailing list by a process of gathering examples of web-publishing behaviour, then codifying it. Some other microformats (such as and
unAPI According to its website, an unAPI is: The unAPI specification is only two pages long. Server-side applications which use unAPI * Bebop Bebop or bop is a style of jazz Jazz is a music genre A music genre is a conventional c ...
) have been proposed, or developed, elsewhere.

Technical overview

XHTML Extensible HyperText Markup Language (XHTML) is part of the family of XML Extensible Markup Language (XML) is a markup language #REDIRECT Markup language In computer text processing, a markup language is a system for annotation, annotating ...

and HTML standards allow for the embedding and encoding of semantics within the attributes of markup elements. Microformats take advantage of these standards by indicating the presence of metadata using the following attributes: ; class : Classname ; rel : relationship, description of the target address in an anchor-element (...) ; rev : reverse relationship, description of the referenced document (in one case, otherwise deprecated in microformats) For example, in the text "The birds roosted at 52.48, -1.89" is a pair of numbers which may be understood, from their context, to be a set of
geographic coordinates Geography (from Greek#REDIRECT Greek Greek may refer to: Greece Anything of, from, or related to Greece Greece ( el, Ελλάδα, , ), officially the Hellenic Republic, is a country located in Southeast Europe. Its population is ap ...
. With wrapping in spans (or other HTML elements) with specific class names (in this case geo, latitude and longitude, all part of the geo microformat specification): The birds roosted at 52.48, -1.89 software agents can recognize exactly what each value represents and can then perform a variety of tasks such as indexing, locating it on a map and exporting it to a
GPS The Global Positioning System (GPS), originally Navstar GPS, is a satellite-based radionavigation system owned by the United States government The federal government of the United States (U.S. federal government or U.S. governme ...



In this example, the contact information is presented as follows: With hCard microformat markup, that becomes: Here, the formatted name (fn), organisation (org), telephone number (tel) and
web address A Uniform Resource Locator (URL), colloquially termed a web address, is a reference to a web resource A web resource is any identifiable resource (digital, physical, or abstract) present on or connected to the World Wide Web The ...

web address
(url) have been identified using specific class names and the whole thing is wrapped in class="vcard", which indicates that the other classes form an hCard (short for "HTML
vCard vCard, also known as VCF (Virtual Contact File), is a file format A file format is a standard Standard may refer to: Flags * Colours, standards and guidons * Standard (flag), a type of flag used for personal identification Norm, ...
") and are not merely coincidentally named. Other, optional, hCard classes also exist. Software, such as browser plug-ins, can now extract the information, and transfer it to other applications, such as an address book.

In-context examples

For annotated examples of microformats on live pages, see HCard#Live example and Geo (microformat)#Usage.

Specific microformats

Several microformats have been developed to enable semantic markup of particular types of information. However, only hCard and hCalendar have been ratified, the others remaining as drafts: * hAtom (superseded by h-entry and h-feed) – for marking up Atom (standard), Atom feeds from within standard HTML * hCalendar – for events * hCard – for contact information; includes: ** adr – for postal addresses ** geo (microformat), geo – for geographical coordinates (latitude, longitude) * hMedia – for audio/video content * hAudio – for audio content * hNews – for news content * hProduct – for products * hRecipe – for recipes and foodstuffs. * hReview – for reviews * rel-directory (file systems), directory – for distributed directory creation and inclusion * rel-enclosure – for multimedia attachments to web pages * rel-license – specification of copyright license * rel-nofollow, an attempt to discourage third-party content spam (e.g. spam in blogs) * rel-tag (metadata), tag – for decentralized tagging (Folksonomy) * XHTML Friends Network (XFN) – for social relationships * XOXO (microformat), XOXO – for lists and outlines


Using microformats within HTML code provides additional formatting and semantic data that applications can use. For example, applications such as web crawlers can collect data about online resources, or desktop applications such as e-mail clients or scheduling software can compile details. The use of microformats can also facilitate "mash ups" such as exporting all of the geographical locations on a web page into (for example) Google Maps to visualize them spatially. Several browser extensions, such as Operator (extension), Operator for Firefox and Oomph for Internet Explorer, provide the ability to detect microformats within an HTML document. When hCard or hCalendar are involved, such browser extensions allow microformats to be exported into formats compatible with contact management and calendar utilities, such as Microsoft Outlook. When dealing with geographical coordinates, they allow the location to be sent to applications such as Google Maps. Yahoo! query language, Yahoo! Query Language can be used to extract microformats from web pages. On 12 May 2009 Google Search, Google announced that they would be parsing the hCard, hReview and hProduct microformats, and using them to populate search result pages. They subsequently extended this in 2010 to use hCalendar for events and hRecipe for cookery recipes. Similarly, microformats are also processed by Bing (search engine), Bing and Yahoo!. As of late 2010, these are the world's top three search engines. Microsoft said in 2006 that they needed to incorporate Microformats into upcoming projects, as did other software companies. Alex Faaborg summarizes the arguments for putting the responsibility for microformat user interfaces in the web browser rather than making more complicated HTML: * Only the web browser knows what applications are accessible to the user and what the user's preferences are * It lowers the barrier to entry for web site developers if they only need to do the markup and not handle "appearance" or "action" issues * Retains backwards compatibility with web browsers that don't support microformats * The web browser presents a single point of entry from the web to the user's computer, which simplifies security issues


Various commentators have offered review and discussion on the design principles and practical aspects of microformats. Microformats have been compared to other approaches that seek to serve the same or similar purpose. , there had been some criticism of one, or all, microformats. The spread and use of microformats was being advocated . This includes community resources for marketing microformats such as buttons, banners, wallpaper / desktop screens, logo graphics, etc. Opera Software CTO and Cascading Style Sheets, CSS creator Håkon Wium Lie said in 2005 "We will also see a bunch of microformats being developed, and that’s how the Semantic Web, semantic web will be built, I believe." However, in August 2008 Toby Inkster, author of the "Swignition" (formerly "Cognition") microformat parsing service, pointed out that no new microformat specifications had been published since 2005.

Design principles

Computer scientist and entrepreneur, Rohit Khare stated that ''reduce, reuse, and recycle'' is "shorthand for several design principles" that motivated the development and practices behind microformats. These aspects can be summarized as follows: *Reduce: favor the simplest solutions and focus attention on specific problems; *Reuse: work from experience and favor examples of current practice; *Recycle: encourage modularity and the ability to embed, valid XHTML can be reused in blog posts,
RSS RSS (Resource Description Framework, RDF Site Summary or Really Simple Syndication) is a web feed that allows users and applications to access updates to websites in a Standardization, standardized, computer-readable format. Subscribing to RSS ...

feeds, and anywhere else you can access the web.


Because some microformats make use of title attribute of HTML's element to conceal machine-readable data (particularly date-times and geographical coordinates) in the
abbr design pattern
, the plain text content of the element is inaccessible to screen readers that expand abbreviations. In June 2008 the BBC announced that it would be dropping use of microformats using the abbr design pattern because of accessibility concerns.

Comparison with alternative approaches

Microformats are not the only solution for providing "more intelligent data" on the web; alternative approaches are used and are under development. For example, the use of XML markup and standards of the Semantic Web are cited as alternative approaches. Some contrast these with microformats in that they do not necessarily coincide with the design principles of "reduce, reuse, and recycle", at least not to the same extent. One advocate of microformats, Tantek Çelik, characterized a problem with alternative approaches: For some applications the use of other approaches may be valid. If the type of data to be described does not map to an existing microformat, RDFa can embed arbitrary vocabularies into HTML, such as for example domain-specific scientific data such as zoological or chemical data for which there is no microformat. Standards such as W3C's GRDDL allow microformats to be converted into data compatible with the Semantic Web. Another advocate of microformats, Ryan King, put the compatibility of microformats with other approaches this way:

Microformats 2

Microformats2 was proposed and discussed during FOOEast, 2010-05-02. Microformats2 was intended to make it easier for authors to publish microformats and for developers to consume them, while remaining backwards compatible Using microformats2, the example above would be marked up as: The birds roosted at 52.48, -1.89 and:

See also

*COinS *Embedded RDF *HTML Microdata *Intelligent agents *JSON-LD *RDFa Lite *S5 (file format) *Schema.org *Simple HTML Ontology Extensions *XMDP





* * *

Further reading

* * Ahmet Soylu, Patrick De Causmaecker, Fridolin Wil
Ubiquitous Web for Ubiquitous Environments: The Role of Embedded Semantics
article in Journal of Mobile Multimedia, Vol. 6, No.1, pp. 26–48, (2010)

External links


Microformats Primer

microformats parser and validator
A four-part discussion of Microformats, UI issues, and possible presentation in Firefox 3 by Alex Faaborg of Mozilla
{{Semantic Web Microformats, Knowledge representation Semantic HTML Semantic Web Web design Web development