What Is a Web Browser and How Does It Work?

A web browser is the app you use on your phone, computer, or tablet to access sites on the internet. Without these software programs, you can't watch YouTube, send emails, or shop online without downloading another app.

The most common browsers include Google Chrome, Apple Safari, Microsoft Edge, and Mozilla Firefox. But dozens more exist, and each one provides different features and levels of privacy.

Keep reading to find out how web browsers work, what makes popular browsers different, and how to make your browsing experience more private and secure.

What is a web browser?

Web browsers act like translators, taking the code that creates web pages and turning it into the images, text, and videos you see on your screen. They use protocols such as HTTP and HTTPS to request and receive information from websites, then use a rendering engine to display that information.

In short, a browser is the program that lets you view and interact with websites without needing to read the code behind them. This means you don’t need to understand hypertext markup language (HTML), JavaScript, or other code to navigate the internet. For example, here’s the HTML code for this page:

And here's the view we see when our browser loads the page:

How does a browser work?

When you type a web page address or uniform resource locator (URL) — such as www.allaboutcookies.org — into your browser or click on a link, you’re giving your browser directions for where you want to go.

Once it knows your destination, your browser sends a request to the server or servers where the web page’s content is stored, then retrieves that content and displays it to you. In other words, you're actually making a list of requests to retrieve content from various resource directories or servers where that page's content is stored.

The web page you requested to see may be made up of content from different sources. Images may come from one server, text content from another, scripts from a third server, and ads from a different server.

Your browser then retrieves the data from each server and uses rendering engine software to translate the web page’s HTML and other code into images and text.

What web browser am I using?

Not sure what browser you're using right now? The information below can help identify your browser and connection:

• Your browser identification information is Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)
• Your IP address is 216.73.216.88
• Your hostname is allaboutcookies.org

The browser identification information is called a user-agent string. It may contain your browser name, operating system, and version information, although some browsers limit or modify these details for privacy. If you're unsure which browser you're using, you can also check its About section in the settings menu.

If you'd rather use a different browser, our guide explains how to change your default browser on your device.

Features of web browsers

Web browsers have several important controls that help you navigate websites and manage your browsing experience. The numbers below correspond to the features labeled in our infographic:

1. Tabs: Tabs let you keep multiple web pages open in the same browser window and easily switch between them.
2. Back and forward buttons: These navigation buttons let you return to a previously visited page or move forward again.
3. Refresh button: Reloads the current web page to display updated content or help resolve loading issues.
4. Address bar: Located near the top of the browser, this is where you type a website's URL or enter a search query.
5. Bookmarks: The bookmarks bar gives you quick access to websites you've saved. You can also use the bookmark button, usually a star, to save the current page.
6. Extensions: The extensions menu lets you access browser add-ons that provide extra features, such as ad blockers, password managers, focus timers, and web clippers.
7. Settings menu: Usually represented by three dots or lines, this menu lets you customize your browser, manage privacy and security settings, and access additional tools.
8. Search box: The search field on a search engine's homepage lets you look for websites, answers, images, and other information. You can also search directly from most browsers' address bars.

Other web browser features to know

Not every browser feature is visible in the infographic. Here are a few others worth knowing about:

• Browser history: Your browser history is a record of the websites you've visited over a certain period. This can help you find information again. If you share a computer, consider using separate browser profiles or signing out of accounts to help protect your privacy.
• Browser window: The main application window that displays web pages. You can open multiple windows, each with its own set of tabs.
• Cookies: Cookies are small pieces of data that websites store in your browser. They can keep you signed in or remember your shopping cart, but they can also raise privacy concerns when used for tracking.
• Home page: You can set a default home page that acts as a starting point when you open your browser or select its home button, if enabled. This might be a favorite website, a search engine, or a customized page.

What are some examples of web browsers?

There are plenty of browser options, and most are fairly similar. However, some are open-source software, while others offer additional features that you might like.

Here's a quick comparison of some popular web browsers and what makes them different:

Web browser	Available on	What makes it different
Google Chrome	Windows, Mac, Linux, Android, iOS	Syncs with Google accounts and supports a wide range of extensions
Apple Safari	Mac, iPhone, iPad	Built into Apple devices with integrated privacy features
Microsoft Edge	Windows, Mac, Linux, Android, iOS	Integrates Microsoft services and Copilot AI features
Mozilla Firefox	Windows, Mac, Linux, Android, iOS	Offers customizable privacy settings and enhanced tracking protection
Brave	Windows, Mac, Linux, Android, iOS	Blocks many ads and trackers by default
Opera	Windows, Mac, Linux, Android, iOS	Includes built-in ad blocking and additional privacy tools
Tor Browser	Windows, Mac, Linux, Android	Routes traffic through the Tor network to help protect your anonymity

Here's a closer look at some of these browsers and their features:

• Apple Safari: Made for Apple devices such as MacBooks, iPhones, and iPads, Safari was released in 2003.
• Google Chrome: Chrome is the most popular web browser in the world. It’s ideal for using a complete Google Workspace experience, including Gmail, YouTube, Google Docs, and Google Drive.
• Microsoft Edge: Edge was created by Microsoft for Windows 10 and 11 in 2015, replacing Internet Explorer, which launched in 1995 and was fully retired in 2022.
• Mozilla Firefox: Created by the Mozilla project, which grew out of the Netscape browser, Firefox was first released in 2004. It's a popular option for people who want customizable privacy protections and an alternative to Chromium-based browsers.
• Brave: Brave is a Chromium-based, open-source browser that offers privacy features, including a built-in ad blocker and tracker protection. Learn more about its protections and limitations in our Brave browser review.
• Opera: Opera is another privacy-focused browser that comes with useful features such as a built-in browser VPN and ad blocker. Its browser VPN is different from a device-wide VPN because it primarily protects traffic within the browser.
• Tor Browser: Tor Browser is designed to help protect your identity and browsing activity by routing traffic through the Tor network. It can also access .onion websites, but it doesn't guarantee complete anonymity. Your activity, browser settings, and the information you share online can still affect your privacy.
• Vivaldi: Vivaldi is a highly customizable browser with built-in tracker and ad-blocking options. One of Vivaldi's most popular features is the ability to view your tabs in a side-by-side tile format. Its interface code isn't entirely open source. Learn more in our breakdown of Vivaldi.

If privacy is your biggest priority, check out our guide to the most secure browsers for a closer comparison of their security features.

What's the difference between a browser and a search engine?

A web browser and a search engine aren't the same thing, although you often use them together. A browser is the software that opens and displays websites, while a search engine helps you find websites and information online.

Web browser	Search engine
Software used to open and interact with websites	A service that helps you find websites and information
Examples include Chrome, Safari, Edge, and Firefox	Examples include Google Search, Bing, and DuckDuckGo
Installed on or available through your device	Usually accessed through a web browser

For example, you might open Google Chrome and use Google Search to look for a recipe. Chrome is the browser displaying the results, while Google Search is the search engine finding them. You can also use a different search engine, such as Bing or DuckDuckGo, within Chrome.

What about AI browsers?

One of the biggest shifts in browsers recently is the rise of artificial intelligence (AI). Many major browsers now include AI assistants that can summarize a page, answer questions about what you’re reading, and help you find information. A newer category, often called “agentic” or AI browsers, goes further, completing multi-step tasks for you such as researching a topic, filling out forms, or comparing products while shopping.

• Google Chrome (Gemini): Chrome integrates Google's Gemini AI to help users understand web pages and perform supported tasks. Depending on the available features and permissions, Gemini can also work with information from multiple tabs.
• Microsoft Edge (Copilot): Edge includes Copilot features that can summarize web content, answer questions, and help with tasks such as comparing information across pages. Access to browsing context depends on the feature and permissions involved.
• Perplexity Comet: An AI-first browser built on Chromium that acts like a personal assistant, offering features such as page summaries, browsing assistance, and supported multi-step tasks.

These features are convenient, but the use of AI agents raise privacy risks. An AI assistant that can access your tabs, emails, or calendar may be able to process sensitive personal information. Before using these tools, review what data they can access, what permissions you've granted, and how your information may be stored or used.

A VPN can help protect your internet connection, but it won't prevent an AI assistant from accessing information you've authorized it to use.

What are HTTP and HTTPS?

HTTP and HTTPS are protocols that browsers use to communicate with websites. HTTP stands for Hypertext Transfer Protocol, while HTTPS stands for Hypertext Transfer Protocol Secure.

The key difference is encryption. HTTPS uses transport layer security (TLS) to encrypt information transmitted between your browser and the website's server. This helps protect information such as passwords and payment details from being intercepted or modified while in transit.

• HTTP: Hypertext Transfer Protocol is used by browsers to send and receive data without built-in encryption.
• HTTPS: Hypertext Transfer Protocol Secure uses an encrypted connection to help protect data exchanged between your browser and a website.

Most modern browsers show connection security information near the address bar. However, HTTPS doesn't automatically mean a website is trustworthy. Scam and phishing websites can also use encrypted connections.

How can I change my browser privacy settings?

Even with growing privacy concerns, 1 in 4 users admit they accept cookies automatically — without checking what data they’re agreeing to share.

You can update your browser's privacy settings to control cookies, manage website permissions, and adjust security protections. The exact steps vary depending on your browser and version. Here's how to find the main privacy settings in Google Chrome:

1. Go to the top right of the browser and select the three dots. Then choose Settings from the drop-down menu.

2. Choose Privacy and security. From here, you can select Delete browsing data (or Clear browsing data, depending on your version) to remove browsing history, cookies, and cached files.

Under Third-party cookies, you can review Chrome's controls for limiting cross-site tracking. You can also manage website permissions and other privacy options. Available settings may differ depending on your browser version and Google's current tracking protection features.

Under Security, you can choose the level of Safe Browsing protection Chrome uses against malicious websites and downloads.

You can also use Safety Check to review security-related settings and identify potential issues, such as outdated browser software or compromised passwords.

5 web browser privacy and security tips

Chrome and other browsers help you secure your online experience by offering different levels of protection or specific features. Here are the five browser privacy and security tips we recommend most.

1. Use incognito mode

If you want additional privacy on a shared device, many browsers offer an incognito or private browsing option. Incognito mode generally doesn't save your browsing history after you close all private windows, and temporary cookies and site data from that session are removed.

However, incognito mode doesn't make you anonymous online. Websites, network administrators, and your internet service provider may still be able to observe aspects of your browsing activity.

On Chrome, you can open an incognito window from the three-dot menu in the top-right corner by selecting New Incognito Window, or by pressing Ctrl + Shift + N (Cmd + Shift + N on a Mac).

2. Use a VPN

You can add another level of privacy by using a virtual private network (VPN). VPN clients establish an encrypted connection between your device and the VPN server, helping protect your internet traffic from people monitoring the local network.

A VPN also replaces the public IP address websites normally see with the VPN server's IP address. Some VPNs include additional features that block malicious websites, ads, or trackers.

However, VPNs don't make you completely anonymous, and they don't replace HTTPS or your browser's built-in security protections. If you're interested in additional privacy features, see our guide to the best VPN services.

3. Use a private search engine

The standard search engines are Google, Bing, and Yahoo, but you might prefer to use a private search engine instead.

Private search engines, like DuckDuckGo and Qwant, emphasize limiting the collection or use of personal information for search tracking and advertising. Their specific privacy practices differ, so it's worth reviewing their policies before choosing one.

4. Use a pop-up blocker

Some pop-up ads are harmless, but some are created by scammers and designed to trick you into giving up your personal information.

You can block pop-ups and redirects inside your browser settings. Third-party ad blockers such as Total Adblock can provide additional protection by blocking many ads and trackers.

5. Delete and disable cookies

Removing cookies can help limit stored tracking information and clear website data from your browser. You can also reject optional cookies when websites provide that choice or adjust your browser settings to limit third-party cookies.

Keep in mind that deleting cookies may sign you out of websites, reset your preferences, or remove items saved in shopping carts. You don't need to block every cookie to improve your privacy.

How have web browsers evolved?

Before the World Wide Web became widely available to the public in the 1990s, the internet was used primarily by researchers, universities, government organizations, and other institutions. Early web pages were mostly text-based and quite simple, as you can see in this replica of the very first web page, which was hosted on Tim Berners-Lee’s (the inventor of the World Wide Web) NeXT computer.

Because web pages started out simple, it makes sense that many of the first web browsers were simple, too. The first browsers had a very specific purpose: to make web page code readable and understandable.

As web developers created more web objects and software libraries, browsers needed to be updated quickly to keep up. Eventually, plug-ins were also developed to extend existing browsers, enabling them to render new types of objects on web pages.

Browsers have changed and continue to change in order to support everything from shopping carts to embedded videos. Private browsers have popped up to address concerns about data privacy and cookie tracking, and the newest browsers now include AI assistants that can read pages and complete tasks for you.

Here’s a list of some of the more well-known browsers and the year they were created:

• Mosaic: 1993
• Netscape Navigator: 1994
• Internet Explorer: 1995 (retired in 2022)
• Opera: 1996
• Mozilla: 1998
• Apple Safari: 2003
• Firefox: 2004
• Google Chrome: 2008
• Microsoft Edge: 2015
• Microsoft Edge (Chromium rebuild): 2020

Bottom line

A web browser is the software that lets you open websites, watch videos, shop online, and interact with content on the internet. Popular browsers like Chrome, Safari, Edge, and Firefox all perform these basic functions, but they differ in their features, device compatibility, and privacy protections.

The best browser for you depends on what you use it for. If convenience and compatibility matter most, a browser that works well with your devices and accounts may be enough. If privacy is a priority, look for features that limit tracking, block unwanted ads, and give you more control over your browsing data.

You can also improve your privacy by reviewing your browser settings and using a secure ad blocker to help reduce unwanted ads and trackers.

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