How to turn off Outlook’s built-in checker when using LanguageTool

If you're using LanguageTool for Windows with Microsoft Outlook, you may see Outlook's own spelling and grammar suggestions alongside LanguageTool’s. This can cause confusion or duplicate feedback.

To keep your writing environment focused and consistent, we recommend turning off Outlook’s native checker. Here's how to do that depending on the version you're using.

In classic Outlook:

1. Open a new message by clicking New Email

2. In the message window, go to the Review tab

3. Click Set Proofing Language…

   

4. Check the box Do not check spelling or grammar

5. Click Set As Default to apply the change

   

In Outlook 365:

1. Open a new message by clicking New mail

2. In the message window, go to the Options tab

3. Click Editor settings under the Editor section

   

4. In the Corrections section, uncheck all available options

5. Click OK to save your changes

   

Once these steps are complete, Outlook will no longer show its own spelling and grammar suggestions, allowing LanguageTool to take over and provide clear, uninterrupted feedback.