25-591: Acid1 , originally called the Box Acid Test , is a test page for web browsers . It was developed in October 1998 and was important in establishing baseline interoperability between early web browsers, especially for the Cascading Style Sheets 1.0 specification. As with acid tests for gold which produce a quick and obvious assessment of the quality of a piece of metal, the web acid tests were designed to produce
50-502: A Chromium -based browser. (Chromium is Google's open-source project that serves as the functional core of Chrome and many other browsers.) Now that Edge has the same API as Chrome, extensions can be installed directly from the Chrome Web Store. In 2015, Mozilla announced that the long-standing XUL and XPCOM extension capabilities of Firefox would be replaced with a less-permissive API very similar to Chrome's. This change
75-428: A clear indication of a browser's compliance to web standards . Acid1 tests many features on one page against a reference image. Acid1 was developed by Todd Fahrner, who was frustrated with the lack of stringent tests to improve browser interoperability. After looking at tests developed by Braden McDaniel that used reference renderings to clarify the intended result, Fahrner developed a comprehensive test that resulted in
100-532: A model, permissions, and a common core of APIs". However, Google joined this during its overhaul of Chrome's extension API, known as Manifest V3 , which greatly reduces the capability of ad blockers and privacy -related extensions. Thus the WebExtensions group is viewed by some extension developers as nothing more than Google imposing its Manifest V3 design. Browser extensions typically have access to sensitive data, such as browsing history , and they have
125-655: A quirky-looking graphic. In 1999, the test was incorporated into the CSS1 test suite. The text used in Acid1 is an allusion to T. S. Eliot's poem The Hollow Men . Acid1 is included as an offline Easter egg in Internet Explorer 5 for Mac OS , accessible by typing ' about: tasman ', with the text replaced by the names of the developers. By early 2008, all major browsers passed the Acid1 test. Acid1 has served as inspiration for Acid2 and Acid3 . Web browser A web browser
150-519: A section in the menu for deleting cookies. Finer-grained management of cookies usually requires a browser extension . The first web browser, called WorldWideWeb , was created in 1990 by Sir Tim Berners-Lee . He then recruited Nicola Pellow to write the Line Mode Browser , which displayed web pages on dumb terminals . The Mosaic web browser was released in April 1993, and was later credited as
175-805: A sync service and web accessibility features. Common user interface (UI) features: While mobile browsers have similar UI features as desktop versions, the limitations of touch screens require mobile UIs to be simpler. The difference is significant for users accustomed to keyboard shortcuts . The most popular desktop browsers also have sophisticated web development tools . Web browsers are popular targets for hackers , who exploit security holes to steal information, destroy files , and other malicious activities. Browser vendors regularly patch these security holes, so users are strongly encouraged to keep their browser software updated. Other protection measures are antivirus software and being aware of scams . Browser extension A browser extension
200-530: A web browser is to fetch content and display it on the user's device. This process begins when the user inputs a Uniform Resource Locator (URL), such as https://en.wikipedia.org/ , into the browser. Virtually all URLs on the Web start with either http: or https: which means they are retrieved with the Hypertext Transfer Protocol (HTTP). For secure mode (HTTPS), the connection between
225-465: Is Google Chrome , with a 67% global market share on all devices, followed by Safari with 18%. A web browser is not the same thing as a search engine , though the two are often confused. A search engine is a website that provides links to other websites. However, to connect to a website's server and display its web pages, a user must have a web browser installed. In some technical contexts, browsers are referred to as user agents . The purpose of
250-629: Is a software module for customizing a web browser . Browsers typically allow users to install a variety of extensions, including user interface modifications, cookie management, ad blocking , and the custom scripting and styling of web pages . Browser plug-ins are a different type of module and no longer supported by the major browsers. One difference is that extensions are distributed as source code , while plug-ins are executables (i.e. object code ). The most popular browser, Google Chrome , has over 100,000 extensions available but stopped supporting plug-ins in 2020. Internet Explorer
275-401: Is an application for accessing websites . When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used on a range of devices, including desktops , laptops , tablets , and smartphones . By 2020, an estimated 4.9 billion people had used a browser. The most-used browser
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#1732855674977300-460: Is based on Mozilla 's code. Both of these codebases are open-source, so a number of small niche browsers are also made from them. The most popular browsers share many features in common. They automatically log users' browsing history , unless the users turn off their browsing history or use the non-logging private mode . They also allow users to set bookmarks , customize the browser with extensions , and can manage user passwords . Some provide
325-408: The most popular browser. Microsoft debuted Internet Explorer in 1995, leading to a browser war with Netscape. Within a few years, Microsoft gained a dominant position in the browser market for two reasons: it bundled Internet Explorer with its popular Windows operating system and did so as freeware with no restrictions on usage. The market share of Internet Explorer peaked at over 95% in
350-569: The ability to alter some browser settings, add user interface items, or replace website content. As a result, there have been instances of malware , so users need to be cautious about what extensions they install. There have also been cases of applications installing browser extensions without the user's knowledge , making it hard for the user to uninstall the unwanted extension. Some Google Chrome extension developers have sold their extensions to third-parties who then incorporated adware . In 2014, Google removed two such extensions from
375-513: The basis for many other browsers, including Microsoft Edge , currently in third place with about a 5% share, as well as Samsung Internet and Opera in fifth and sixth places respectively with over 2% market share each. The other two browsers in the top four are made from different codebases . Safari , based on Apple 's WebKit code, is the second most popular web browser and is dominant on Apple devices, resulting in an 18% global share. Firefox , in fourth place, with about 3% market share,
400-494: The browser and web server is encrypted , providing a secure and private data transfer. Web pages usually contain hyperlinks to other pages and resources. Each link contains a URL, and when it is clicked or tapped , the browser navigates to the new resource. Most browsers use an internal cache of web page resources to improve loading times for subsequent visits to the same page. The cache can store many items, such as large images, so they do not need to be downloaded from
425-646: The early 2000s. In 1998, Netscape launched what would become the Mozilla Foundation to create a new browser using the open-source software model. This work evolved into the Firefox browser, first released by Mozilla in 2004. Firefox's market share peaked at 32% in 2010. Apple released its Safari browser in 2003; it remains the dominant browser on Apple devices, though it did not become popular elsewhere. Google debuted its Chrome browser in 2008, which steadily took market share from Internet Explorer and became
450-682: The first web browser to find mainstream popularity. Its innovative graphical user interface made the World Wide Web easy to navigate and thus more accessible to the average person. This, in turn, sparked the Internet boom of the 1990s, when the Web grew at a very rapid rate. The lead developers of Mosaic then founded the Netscape corporation, which released the Mosaic-influenced Netscape Navigator in 1994. Navigator quickly became
475-508: The most popular browser in 2012. Chrome has remained dominant ever since. By 2015, Microsoft replaced Internet Explorer with Edge for the Windows 10 release. Since the early 2000s, browsers have greatly expanded their HTML , CSS , JavaScript , and multimedia capabilities. One reason has been to enable more sophisticated websites, such as web apps . Another factor is the significant increase of broadband connectivity in many parts of
500-461: The same or very similar API due to the popularity of Google Chrome . Chrome was the first browser with an extension API based solely on HTML , CSS , and JavaScript . Beta testing for this capability began in 2009, and the following year Google opened the Chrome Web Store . As of June 2012, there were 750 million total installations of extensions and other content hosted on the store. In
525-432: The same year, Chrome overtook Internet Explorer as the world's most popular browser, and its usage share reached 60% in 2018. Because of Chrome's success, Microsoft created a very similar extension API for its Edge browser, with the goal of making it easy for Chrome extension developers to port their work to Edge. But after three years Edge still had a disappointingly small market share, so Microsoft rebuilt it as
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#1732855674977550-401: The server again. Cached items are usually only stored for as long as the web server stipulates in its HTTP response messages. During the course of browsing, cookies received from various websites are stored by the browser. Some of them contain login credentials or site preferences. However, others are used for tracking user behavior over long periods of time, so browsers typically provide
575-405: The world, enabling people to access data-intensive content, such as streaming HD video on YouTube , that was not possible during the era of dial-up modems . Google Chrome has been the dominant browser since the mid-2010s and currently has a 67% global market share on all devices. The vast majority of its source code comes from Google's open-source Chromium project; this code is also
600-481: Was enacted in 2017. Firefox extensions are now largely compatible with their Chrome counterparts. Apple was the last major exception to this trend, but support for extensions conforming to the Chrome API was added to Safari for macOS in 2020. Extensions were later enabled in the iOS version for the first time. In 2021, these browser vendors formed a new W3C community group, called WebExtensions, to "specify
625-573: Was the first major browser to support extensions, with the release of version 4 in 1997. Firefox has supported extensions since its launch in 2004. Opera and Chrome began supporting extensions in 2009, and Safari did so the following year. Microsoft Edge added extension support in 2016. In 2015, a community group formed under the W3C to create a single standard application programming interface (API) for browser extensions. While this particular work did not reach fruition, every major browser now has
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