A Chrome extension is a small program that adds a new feature or tool to your Chrome browser
When you install an extension, it lives inside Chrome and changes what the browser can do. An extension might add a button to your toolbar, block ads on websites, save passwords, translate text, or organize your tabs. Unlike a full program you read and install on your computer, an extension only works inside Chrome itself — it does not run when Chrome is closed.
Extensions are built by Google, by other companies, and by individual developers. You find them in the Chrome Web Store, which is Google's official marketplace. Some extensions are free; others cost money. Most people use between zero and five extensions at any given time, depending on what tasks they do most often.
Key Takeaways
- An extension is a small add-on program that runs inside Chrome and adds a specific feature or tool you choose to install.
- Extensions live in the Chrome Web Store, where you can read reviews and see what permissions each one needs before you install it.
- Once installed, an extension usually shows a button in your toolbar, and you control whether it runs on all websites or only the ones you pick.
- Extensions can slow Chrome down if you install too many, so most people keep only the ones they use regularly.
- You can turn an extension off, remove it entirely, or change what websites it can see without uninstalling it.
How extensions differ from regular browser features
Chrome comes with built-in features like bookmarks, a search bar, and a history page. Those features are part of Chrome itself and cannot be removed. An extension is different — it is optional software you choose to add, and you can remove it at any time.
A second difference is how much access they have. A built-in feature like your bookmark list only touches your bookmarks. An extension you install can be given permission to see the websites you visit, read the text on a page, change what you see, or store information on your computer. Before you install an extension, Chrome shows you exactly what permissions it is asking for — and you decide whether to grant them.
Where extensions come from and how to find them
The Chrome Web Store is the official place to find extensions. You reach it by opening Chrome, clicking the three vertical dots in the top right corner, then selecting "More tools" and "Extensions." From there, a link takes you to the Web Store. You can also search for "Chrome Web Store" in Google.
In the Web Store, you can search by what you want to do — "password manager," "ad blocker," "grammar checker" — and see a list of extensions that do that job. Each extension has a page showing its description, user reviews, how many people use it, and what permissions it needs. Read the reviews and the permissions before you install anything, because that tells you whether other people found it useful and what access you are giving it.
Never install an extension from anywhere except the Chrome Web Store. Websites that claim to offer extensions outside the Web Store are often unsafe and can put your computer or your personal information at risk.
What permissions mean and why extensions ask for them
When you try to install an extension, Chrome shows you a list of permissions — things the extension is asking permission to do. A password manager might ask to "read and change all your data on websites you visit" because it needs to see login forms and fill them in. An ad blocker needs to see the content on every page so it can identify and hide ads. A grammar checker needs to read the text you type.
The key rule is this: if an extension is asking for permissions that seem too broad for what it claims to do, do not install it. If a straightforward note-taking extension asks for permission to see all your browsing history, that is a red flag. If a weather extension asks to read all your data on all websites, that does not make sense. Read the reviews — if other users mention that an extension seems to ask for too much access, trust that warning.
How to install and manage extensions
To install an extension, find it in the Chrome Web Store, click the blue "Add to Chrome" button, and confirm when Chrome asks if you want to add it. The extension usually appears as a small icon in your toolbar — the row of buttons in the top right of your browser window. Click that icon to use the extension or to see its settings.
To see all your installed extensions, click the three vertical dots in the top right, select "More tools," then "Extensions." This page shows every extension you have installed, whether it is turned on or off, and what permissions it has. You can turn an extension off by clicking the toggle switch next to its name — this stops it from running but keeps it installed. You can remove it entirely by clicking the trash icon.
If an extension is slowing Chrome down, the Extensions page shows you how much memory and processing power each one is using. Removing extensions you do not use regularly is the fastest way to speed Chrome back up.
Controlling which websites an extension can see
By default, most extensions run on every website you visit. You can change this so an extension only works on specific websites. On the Extensions page, click "Details" for any extension, then scroll down to "Site access." You have three choices: "On all sites," "On specific sites," or "On click only."
"On click only" means the extension does nothing unless you click its icon in the toolbar. This is useful if you have an extension you only need sometimes — like a translation tool you use once a week. "On specific sites" lets you type in website addresses where the extension should work. If you have a password manager, you might set it to work on banking sites and email but nowhere else, giving it less access overall.
Common reasons to use extensions
Password managers like Bitwarden or 1Password store your login information securely and fill in passwords for you. Ad blockers like uBlock Origin remove advertisements from websites. Grammar checkers like Grammarly review text you type and suggest corrections. Tab organizers help you manage dozens of open tabs. Video downloaders let you save videos from websites. Dark mode extensions change bright websites to dark backgrounds for easier reading at night.
The extension you choose depends on what you do most often in Chrome. If you shop online frequently, a price comparison extension might save you money. If you watch videos, a video player extension might add features. If you read a lot, a reading mode extension might make text easier to focus on. Start with one or two extensions that solve a real problem for you, then add more only if you find yourself wishing Chrome could do something it cannot.
Frequently Asked Questions
Can an extension steal my passwords or personal information?
An extension with permission to see your data could theoretically do this, which is why you should only install extensions from the Chrome Web Store and only ones with good reviews. If an extension seems suspicious or asks for permissions that do not match what it claims to do, do not install it. You can also check what permissions each extension has on the Extensions page and remove it if you become uncomfortable with it.
Will extensions slow down my Chrome browser?
Yes, each extension uses some memory and processing power. If you install many extensions, Chrome will run slower. The Extensions page shows you how much each one is using. Remove extensions you do not use regularly, and you will notice Chrome speed up again.
What is the difference between an extension and a theme?
A theme changes how Chrome looks — the colors, the background, the fonts. An extension adds a new feature or tool. You can use both at the same time. Themes are also found in the Chrome Web Store and installed the same way.
Can I use the same extension on multiple computers?
Yes. If you sign into your Google account on another computer and use Chrome, your extensions install automatically on that computer too. This also syncs your extension settings across devices, so your password manager or ad blocker works the same way everywhere you use Chrome.
What happens to my extensions if I uninstall Chrome?
When you uninstall Chrome, your extensions are removed too. When you reinstall Chrome and sign into your Google account, your extensions install again automatically. Any data the extensions stored — like saved passwords or settings — comes back as well.