Web browser

A web browser is a software tool used to visit websites. When someone wants to view a page on a specific site, the browser pulls the necessary files from a web server and shows the page on the screen. It can also display content saved directly on the user's own device. Browsers run on many types of hardware, such as desktop computers, laptops, tablets, smartphones, smartwatches, smart TVs, and game consoles. By 2026, the most widely used browsers worldwide included Google Chrome (roughly 69% of the market), Safari (about 16%), Edge (around 5%), Firefox (about 2%), Samsung Browser (about 2%), and Opera (about 2%). As of 2023, an estimated 5.4 billion people had used a browser at some point.

**Function**

The main job of a web browser is to retrieve content and present it on a device. This starts when a user types a Uniform Resource Locator (URL), like https://en.wikipedia.org/, into the browser's address bar. Nearly all web URLs begin with http: or https:, meaning they are fetched using the Hypertext Transfer Protocol (HTTP). When HTTPS is used, the connection between the browser and the server is encrypted, which keeps data transfers secure and private. Because of this, a browser is often called an HTTP client or a user agent. The browser downloads the needed materials—text, style sheets, images, and other multimedia—from the server. After downloading, the browser's engine (also called a layout engine or rendering engine) turns those resources into an interactive visual page on the user's screen. Modern browsers also include separate JavaScript engines, which allow more complex interactive applications to run inside the browser. A browser that does not show a graphical interface is called a headless browser.

Web pages typically contain hyperlinks to other pages or resources. Each link has a URL, and when clicked or tapped, the browser moves to that new resource. Most browsers use an internal cache to store web page resources, which speeds up loading times when the user revisits the same page. The cache can hold many items, like large images, so they don't have to be downloaded again from the server. Cached items are usually kept only as long as the web server allows in its HTTP response messages.

A web browser is not the same as a search engine, even though people often mix them up. A search engine is a website that gives links to other sites and lets users search for specific resources with a text query. However, browsers are commonly used to reach search engines, and most modern browsers let users type a query directly into the address bar to use a default search engine.

**History**

The very first web browser, named WorldWideWeb, was built in 1990 by Sir Tim Berners-Lee. He then brought in Nicola Pellow to create the Line Mode Browser, which showed web pages on dumb terminals. The Mosaic browser came out in April 1993 and is often credited as the first browser to gain mainstream popularity. Its graphical user interface made the World Wide Web easier to navigate and more accessible to ordinary people, which helped spark the Internet boom of the 1990s, when the Web grew extremely fast. The lead developers of Mosaic then started the Netscape corporation, releasing the Mosaic-influenced Netscape Navigator in 1994. Navigator quickly became the most popular browser.

Microsoft launched Internet Explorer in 1995, starting a browser war with Netscape. Within a few years, Microsoft had a dominant position in the browser market for two reasons: it bundled Internet Explorer with its widely used Windows operating system and offered it as freeware with no usage restrictions. Internet Explorer's market share peaked at over 95% in the early 2000s. In 1998, Netscape started what would become the Mozilla Foundation, aiming to create a new browser using an open-source software model. This work led to the Firefox browser, first released by Mozilla in 2004. Firefox's market share peaked at 32% in 2010. Apple released Safari in 2003; it remains the leading browser on Apple devices but never became popular elsewhere.

Google launched Chrome in 2008, and it steadily took market share from Internet Explorer, becoming the most popular browser in 2012. Chrome has stayed dominant ever since. In 2015, Microsoft replaced Internet Explorer with Edge (the legacy version) for the Windows 10 release. In 2020, that legacy version was replaced by a new Chromium-based version of Edge. Since the early 2000s, browsers have greatly expanded their support for HTML, CSS, JavaScript, and multimedia. One reason has been to allow more sophisticated websites, such as web apps. Another factor is the significant increase in broadband connectivity in many parts of the world, which lets people access data-heavy content—like streaming HD video on YouTube—that was impossible during the dial-up modem era. Starting in the mid-2020s, browsers with built-in artificial intelligence (AI) capabilities, called AI browsers, became more common. This includes both new entrants to the market, such as Perplexity Comet and ChatGPT Atlas, and established browsers that added AI features, like Chrome with the Gemini chatbot and Edge with the Copilot chatbot.

**Features**

The most popular browsers share many features. They automatically record users' browsing history unless the user turns it off or uses a private mode that does not log activity. They also let users set bookmarks, customize the browser with extensions, and manage downloads and passwords. Some offer a sync service and web accessibility features. Common user interface features include allowing the user to have multiple pages open at the same time, either in different windows or in tabs.