How to Enable Dark Mode in Microsoft Outlook

Reducing Eye Strain and Improving Readability

If you spend a significant portion of your workday staring at a bright white email inbox, you are likely no stranger to digital eye strain and fatigue. To help combat this, Microsoft has integrated a comprehensive Dark Mode into the entire Office 365 suite, including Microsoft Outlook.

Dark Mode completely inverts the standard colour palette, swapping the glaring white background for deep greys and blacks, and changing the standard black text to white or light grey. Not only is this significantly easier on the eyes—especially in low-light environments—but it can also save battery life on laptops with OLED displays.

Here is how to enable Dark Mode across all versions of Microsoft Outlook, including the desktop application, the web version, and the mobile app.

How to Enable Dark Mode in the Outlook Desktop App (Windows)

If you use the traditional Microsoft Outlook desktop program installed on your Windows PC as part of an Office 365 subscription, the dark theme is applied at the account level. Changing it in Outlook will also change the theme in Word and Excel.

1. Open the Microsoft Outlook desktop application.
2. Click on the File tab in the top-left corner of the ribbon menu.
3. Look at the very bottom of the left-hand sidebar and click on Options (or Office Account depending on your version).
4. In the Options window, make sure the General tab is selected on the left.
5. Look for the section labelled “Personalize your copy of Microsoft Office.”
6. Click the drop-down menu next to Office Theme.
7. Select Black (for true dark mode) or Dark Gray (for a slightly softer, lighter dark theme).
8. Click OK at the bottom of the window to save your changes.

Pro Tip: Reading Emails in White
Sometimes, an email with a complex HTML layout (like a newsletter) will look broken in Dark Mode. You can temporarily toggle the reading pane back to a white background by clicking the small Sun/Moon icon located right next to the Reply/Forward buttons inside the email itself.

How to Enable Dark Mode in Outlook on the Web

If you check your email through a web browser at Outlook.com, the interface is completely separate from your desktop software and must be changed independently.

1. Open your web browser and log in to Outlook.com.
2. Click the Settings icon (the gear cog) in the top-right corner of the screen.
3. A quick settings panel will slide out from the right. Look for the Dark mode toggle switch and turn it On.

If you do not see the quick toggle, click View all Outlook settings at the bottom of the panel, go to General > Appearance, and select the Dark theme from there.

How to Enable Dark Mode on the Outlook Mobile App (iOS & Android)

The Outlook mobile app will usually default to whatever system-wide theme your phone is currently using. For example, if your iPhone goes into Dark Mode at sunset, Outlook will automatically follow suit. However, you can force the app to stay in Dark Mode permanently.

1. Open the Outlook app on your iPhone or Android device.
2. Tap your profile picture (or the Home icon) in the top-left corner to open the side menu.
3. Tap the Settings icon (the gear) at the bottom-left corner of the menu.
4. Scroll down to the “Preferences” section and tap Appearance (or Theme).
5. You will have three choices: Light, Dark, or System Default. Tap Dark to lock the app into Dark Mode permanently, regardless of what the rest of your phone is doing.