Aweb browser, often shortened tobrowser, is anapplication for accessingwebsites. When auser requests aweb page from a particular website, the browser retrieves itsfiles from aweb server and then displays the page on the user's screen. Browsers can also display content stored locally on the user's device.
The purpose of a web browser is to fetch content and display it on the user's device.[4] This process begins when the user inputs aUniform Resource Locator (URL), such ashttps://en.wikipedia.org/, into the browser'saddress bar. Virtually all URLs onthe Web start with eitherhttp: orhttps: which means they are retrieved with theHypertext Transfer Protocol (HTTP). Forsecure mode (HTTPS), the connection between the browser andweb server isencrypted, providing asecure andprivate data transfer.[5] For this reason, a web browser is often referred to as an HTTP client[6][7] or auser agent. Requisite materials, including text,style sheets,images, and other types ofmultimedia, aredownloaded from the server. Once the materials have been downloaded, the web browser'sengine (also known as a layout engine or rendering engine) is responsible for converting those resources into an interactive visual representation of the page on the user's device.[8] Modern web browsers also contain separateJavaScript engines which enable more complex interactive applications inside the browser.[9] A web browser that does not render agraphical user interface is known as aheadless browser.
Web pages usually containhyperlinks to other pages and resources. Each link contains a URL, and when it isclicked ortapped, the browser navigates to the new resource. Most browsers use an internalcache 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 the server again. Cached items are usually only stored for as long as the web server stipulates in its HTTP response messages.[10][11]
A web browser is not the same thing as asearch engine, though the two are often confused.[12][13] A search engine is a website that provideslinks to other websites and allows users to search for specific resources using a textualquery. However, web browsers are often used to access search engines, and most modern browsers allow users to access a default search engine directly by typing a query into the address bar.[14]
The first web browser, calledWorldWideWeb, was created in 1990 by SirTim Berners-Lee.[15][16] He then recruitedNicola Pellow to write theLine Mode Browser, which displayed web pages ondumb terminals.[17] TheMosaic web browser was released in April 1993, and was later credited as the first web browser to find mainstream popularity.[18][19] Its innovativegraphical user interface made theWorld 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.[19] The lead developers of Mosaic then founded theNetscape corporation, which released the Mosaic-influencedNetscape Navigator in 1994. Navigator quickly became themost popular browser.[20]
Microsoft debutedInternet Explorer in 1995, leading to abrowser 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 popularWindowsoperating system and did so asfreeware with no restrictions on usage. The market share of Internet Explorer peaked at over 95% in the early 2000s.[21] In 1998, Netscape launched what would become theMozilla Foundation to create a new browser using theopen-source software model. This work evolved into theFirefox browser, first released by Mozilla in 2004. Firefox's market share peaked at 32% in 2010.[22]Apple released itsSafari browser in 2003; it remains the dominant browser on Apple devices, though it did not become popular elsewhere.[23]
Google debuted itsChrome browser in 2008, which steadily took market share from Internet Explorer and became the most popular browser in 2012.[24][25] Chrome hasremained dominant ever since.[1] In 2015, Microsoft replaced Internet Explorer withEdge [Legacy] for theWindows 10 release.[26] In 2020, this legacy version was replaced by a newChromium-based version ofEdge.
Since the early 2000s, browsers have greatly expanded theirHTML,CSS,JavaScript, andmultimedia capabilities. One reason has been to enable more sophisticated websites, such asweb apps. Another factor is the significant increase ofbroadband connectivity inmany parts of the world, enabling people to access data-intensive content, such asstreamingHD video onYouTube, that was not possible during the era ofdial-up modems.[27]
Starting in the mid-2020s, browsers with integratedartificial intelligence (AI) capabilities, known asAI browsers, have become increasingly common. This includes both new entrants to the browser market and established browsers that added AI features, such as Chrome with theGeminichatbot and Edge with theCopilot chatbot.[28][29]
Allowing the user to have multiplepages open at the same time, either in different browser windows or in differenttabs of the same window.
Back andforward buttons to go back to the previous page visited or forward to the next one.
Arefresh orreload and astop button to reload and cancel loading the current page. (In most browsers, the stop button is merged with the reload button.)
An address bar to input theURL of a page and display it, and a search bar to inputqueries into asearch engine. (In most browsers, the search bar is merged with the address bar.)
Whilemobile browsers have similar UI features asdesktop versions, the limitations of the often-smallertouch screens require mobile UIs to be simpler.[34] The difference is significant for users accustomed tokeyboard shortcuts.[35]Responsive web design is used to create websites that offer a consistent experience across the desktop and mobile versions of the website and across varying screen sizes. The most popular desktop browsers also have sophisticatedweb development tools.[36]
Access to some web content — particularlystreaming services like Netflix, Disney+, and Spotify — is restricted byDigital Rights Management (DRM) software. A web browser is able to access DRM-restricted content through the use of aContent Decryption Module (CDM) such asWidevine. As of 2020, the CDMs used by dominant web browsers require browser providers to pay costly license fees, making it unfeasible for most independent open-source browsers to offer access to DRM-restricted content.[37]
Google Chrome has been the dominant browser since the mid-2010s and currently has a 66% global market share on all devices.[1] The vast majority of itssource code comes from Google'sopen-sourceChromium project;[38] this code is also the basis formany other browsers, includingMicrosoft Edge, currently in third place with about a 5% share,[1] as well asSamsung Internet andOpera in fifth and sixth places respectively with approximately 2% market share each.[1]
The other two browsers in the top four are made from differentcodebases.Safari, based onApple'sWebKit code, is the second most popular web browser and is dominant on Apple devices, resulting in an 18% global share.[1]Firefox, in fourth place, with about 3% market share,[1] is based onMozilla's code. Both of these codebases are open-source, so a number of small niche browsers are also made from them.
The following table details the top web browsers by market share, as of February, 2025:
Prior to late 2016, the majority of web traffic came from desktop computers. However,since then, mobile devices (smartphones) have represented the majority of web traffic.[39] As of February 2025, mobile devices represent a 62% share of Internet traffic, followed by desktop at 36% and tablet at 2%.[40]
Web browsers are popular targets forhackers, who exploitsecurity holes to steal information, destroyfiles, and partake in othermalicious activities. Browser vendors regularly patch these security holes, so users are strongly encouraged to keep their browser software updated. Other protection measures areantivirus software and being aware ofscams.[41]
During the course of browsing,cookies received from variouswebsites are stored by the browser. Some of them contain login credentials or site preferences.[42] However, others are used for tracking user behavior over long periods of time, so browsers typically provide a section in the menu for deleting cookies.[42] Some browsers have more proactive protection against cookies and trackers that limit their functionality and ability to track user behaviour.[43] Finer-grained management of cookies usually requires abrowser extension.[44]Telemetry data iscollected by most popular web browsers, which can usually be opted out of by the user.[45]
^What is a Browser?. Google (on YouTube). 30 April 2009.Archived from the original on 9 May 2018. Retrieved23 April 2018.Less than 8% of people who were interviewed on this day knew what a browser was.
^Ioannou, Pantelina; Athanasopoulos, Elias (1 July 2023). "Been Here Already? Detecting Synchronized Browsers in the Wild".2023 IEEE 8th European Symposium on Security and Privacy (EuroS&P). IEEE. pp. 913–927.doi:10.1109/EuroSP57164.2023.00058.ISBN978-1-6654-6512-0.
.png)
