What is a browser extension and how does it work?
A browser extension is like an app for your web browser. While browser extensions can boost productivity and customize your browsing experience, some may collect data or even open the door to malware and other security risks. These apps add new features or tools such as blocking ads or checking your grammar without having to leave the site you’re on.
These add-ons work by plugging directly into your browser (like Chrome, Firefox) and interacting with the pages you visit.
Most are built using web technologies like HTML and JavaScript. Once installed, they live in your browser’s toolbar or menu, quietly doing their job in the background and potentially popping up when you need them.
What can browser extensions do?
Browser extensions can do everything from blocking pop-ups to remembering your passwords and helping you write better emails. They’re designed to make your browsing easier and more personalized.
People install these add-ons to save time, stay organized, or get more out of their favorite websites. Popular ones include password managers or ad blockers like Malwarebyte Browserguard ad blocker, and shopping tools like Honey that can apply discounts or codes when people are shopping. These tools can be incredibly useful.
Are browser extensions safe?
Browser extensions are often safe, but they also pose risks in some scenarios, especially when they request broad permissions or come from unverified sources. Some extensions collect user data like browsing history or keystrokes, often under the guise of functionality.
There have been real-world cases of malicious browser extensions making headlines. Malicious Chrome extensions have at times been caught showing hidden ads and collecting personal data. Even trusted extensions can turn shady if they’re bought out or updated with harmful code. A 2024 study by Georgia Tech University found that thousands of extensions compromise data.
An example called Finance Simplified that claimed to help people manage their finances was installed over 100,000 times, but turned out to be stealing data and using it for blackmail.
A malicious extension is one that exploits the permissions given when installing it to spy or manipulate your browsing experience without consent. The danger is that they often look perfectly normal until it’s too late.
How to stay safe when using browser extensions
Browser extension security is something that requires a bit of consideration. Staying safe means being selective and cautious.
Only download from trusted sources
Stick to official browser stores. This usually means:
- Chrome Web Store
- Firefox Add-ons
- Microsoft Edge Add-ons
These platforms run basic security checks that third-party sites might not, helping to protect customers. It means there has been some level of testing and compliance. Never download an extension from a random pop-up or unknown link.
Read the reviews – but look for red flags
User reviews can reveal a lot. People may see reports of things like unexpected pop-ups, suspicious behavior, or sudden changes after an update. Be cautious if you see vague reviews or tons of 5-star ratings with no detail. Reviews can be faked.
Check what permissions the extension wants
Before installing, check the permissions it asks for.
Does a calculator need access to all your browsing data? Probably not. It can be a sign of an extension trying to get more access than its function suggests, and that’s a red flag. The fewer permissions given up, the better.
Don’t install more than you need
Each extension adds a new layer of risk, especially if you’re not actively using it. Limit your installs to tools you rely on regularly. The more you have, the bigger your risk potentially becomes.
Remove anything you’re not using
If you haven’t used an extension in weeks (or forgot you even had it), it’s time to uninstall it. Extensions can run in the background and still have access to your data, even if you never click on them.
Where to find and install browser extensions (safely)
The safest way to find and install browser extensions is through your browser’s official store. These platforms screen for malicious behavior and make it easier to spot trustworthy, well-reviewed tools. Even in official stores, it’s important to watch out for fake or copycat versions of popular extensions and to always double-check the publisher.
Installing and removing extensions is simple: just go to your browser’s extension store, search for what you need, and click “Add” or “Install.” To remove one, go to your browser’s extension settings and click “Remove” next to any you no longer want.
Chrome
- Visit the Chrome Web Store to search for extensions by name or category.
- Click “Add to Chrome,” then confirm the installation.
- To manage or remove extensions, go to chrome://extensions/ in your address bar.
- Always verify the publisher and check user reviews before installing.
Firefox
- Head to the Firefox Add-ons site.
- Once you find an extension, click “Add to Firefox” and grant the requested permissions.
- Manage or remove extensions by clicking the puzzle piece icon in the toolbar or navigating to about:addons in your browser.
Safari
- Safari extensions are available through the Mac App Store, not a browser-based marketplace.
- Search for “Safari Extensions,” download the app, then enable it in Safari’s preferences under the “Extensions” tab.
- Be extra cautious, as the selection is smaller and third-party sources are riskier.
Microsoft Edge
- Go to the Edge Add-ons store to browse and install extensions.
- Click “Get,” then confirm. You can manage your extensions by clicking the puzzle icon or going to edge://extensions/.
- Edge also allows you to install Chrome extensions, but stick to trusted sources.
When extensions don’t get along: extension conflicts
Extension conflicts happen when two or more browser add-ons interfere with each other. It usually causes issues like pages that load incorrectly or your browser to slow down. It’s more common than you might think, especially with ad blockers, privacy tools, and performance boosters.
If your browser starts acting up after installing a new extension, that’s often your first clue. Websites might break, buttons may disappear, or the browser might crash. One easy fix: disable them one at a time to find the culprit. Once identified, you can choose to remove it or find an alternative that works with the others.
Do you really need that extension?
Before installing a browser extension, ask yourself: What does this actually do and is it worth the privacy or security risk? Some offer helpful features, but many duplicate tools your browser already has or ask for more access than they need.
Take a closer look at what your browser can already handle and use an ad blocker such as Malwarebytes Browserguard ad blocker to protect your privacy.
It’s worth pausing before clicking “Install.” Less is often more when it comes to add-ons and browser extensions.
Check out this list of malicious browser extensions.