- Click on the Chrome menu icon (three vertical dots on the top right of your screen)
- Click Settings
- Scroll down to the Autofill section
- Click the type of data you want to disable
- Use the toggles to disable
In the Autofill section, you'll be able to manage Autofill for multiple categories of data. To manage Autofill for each category, click on the category name, and then use the toggles to enable or disable Autofill.
- Click on the Firefox menu icon (three lines at the top right of your screen)
- Click Preferences
- Click Privacy & Security
- Scroll down to the Forms and Autofill section
- Use the checkboxes to disable Autofill for each type of data
If security is your concern, you might consider leaving Autofill enabled and telling Firefox to require macOS authentication to actually fill out forms. You can manage that setting in this section as well.