Browser extensions and add-ons: What are they and are they safe to use?

Do you wish your internet browser offered a spell checker? Would you like to block ads from popping up in your browser window? Looking for an accountability buddy to keep you from surfing for hours? All of this is possible – with browser extensions.
Like other software on your computer, every web browser can be customized. Add-ons and extensions let you add features to tailor your browsing experience to your needs. But what exactly is a web browser extension?

by Alyssa Schmitt
Smiling woman working on computer at home
Extensions can make browsing more fun because you can customize your experience

What is a web browser extension?

“Extensions,” sometimes also called “add-ons,” are an individual and optional supplement to an existing computer program. They are not stand-alone applications – they only work together with the primary software program. A good example of this are the spell- and grammar-check features offered by Grammarly, which you can add on to another program that you use for writing. So, you might install the Grammarly add-on for Microsoft Office to proofread documents you are writing in Word, PowerPoint, etc., or use the Grammarly extension for the Chrome browser to check your writing in your emails, LinkedIn posts, etc. In doing so, you have extended or added onto the functions of the program that you already use.

Are browser extensions a security risk?

Browser add-ons and extensions are usually software modules that are developed by third parties and validated by the web browser provider. There have been cases in recent years of cybercriminals using extensions to spread malware. Other extensions can track your browsing behavior across all websites you visit with the aim of delivering targeted advertising. To stay safe, you should only download extensions from official sources, check privacy policies if you are concerned about tracking, and make sure your computer’s antivirus program is up to date.

Is there a difference between add-ons and extensions?

You may have heard the term “add-on” used in several different contexts. That’s because the definition of an add-on is quite broad – there is both software and hardware that can be described as an “add-on,” as long as its purpose is to enhance the functionality of a primary unit or program. One of the most common uses of the phrase “add-on” is to describe an extension to internet browsers.

Good to know: Add-on vs plug-in

In the context of web browsers, an add-on or extension is a software module that expands the functionality of the browser to perform a specific task. Plug-ins are software that serve the same purpose of adding a feature to the browser, but they are different sort of module that uses a different type of code (binary vs. source code). Because plug-ins had a history of causing performance and security issues for users, they are no longer supported by major browsers. The most well-known example of a no-longer available browser plug-in is the Adobe Flash player.

Extensions for your web browser

All the major web browser programs let you install a wide range of add-ons directly in the browser – you can simply go to your browser’s extension menu, which is often represented by an icon in the shape of a puzzle piece. Or follow the links below to the different browser sites. Please note that these are the official stores; as with other programs, to protect your security we recommend that you always use official sources for downloading add-ons.

Find extensions for your favorite browser here:

Pro tip: Mail Collector, the browser add-on

Have you heard about the MailCheck add-on for your browser? It allows you to receive browser notifications when you get a new email and stay logged in at all times. Learn how to use the MailCheck extension: How to use MailCheck to stay logged in to your email

If you’d like to read more about web browsers, including how to change your default browser, see our deep dive: What is a web browser? And before you start customizing your browser with add-ons and extensions, we look forward to your feedback below! is the right email address for everyone! If you don’t have one yet, why not create a email account today?
Images: 1&1/Getty Images

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