Dark Mode for Outlook is a free and open source Chrome extension you can use. It turns the Outlook.com’s bright UI to dark entirely and also hides the ad sidebar. This extension works instantaneously after installtion and you just leave it there. This extension is an open source project and you can also inspect its source which is available on GitHub and even contribute to its code as well.
If you use Outlook.com for personal or work use then one thing that seems a bit off about it is that they haven’t yet introduced dark mode for the web. The dark mode exits only for the mobile app and if you want to have it on the web as well then you will have to rely on third party options. And once such option here is this extension that I have mentioned here. Just install it to have dark mode on Outlook.com instantly.
Add Dark Mode to Outlook.com, Remove Ad Sidebar with this Extension
This Dark Mode for Outlook works on other browsers as well part from Chrome, such as Firefox and Opera. You can download it from its GitHub repository or you can also install it from Chrome web store. If there is Outlook.com tab is opened then just keep it opened.
After the extension installs successfully, it will automatically add dark mode on Outlook. Also, the ad sidebar will be removed. All you have to do is refresh the page and let the main viewing area occupy more space. When the sidebar is gone, you will not see ads and will have a bigger area for mail preview. You can see this behavior in the screenshot below.
In this way, you can use this simple Chrome extension to add dark mode to Outlook.com. The process is very simple and you can follow it on other browsers as well such as Firefox.
If you are an Outlook.com user then you will find this browser plugin really handy. Just turn dark mode on Outlook in just a few clicks without complicated setup. I liked the straightforwardness of the plugin and the best part is that you will get rid of Outlook ads as well.