macOS includes a deeply integrated password management system called iCloud Keychain. When you use the Safari web browser, Keychain constantly monitors the websites you visit. If it detects a login form (a username field and a password field), it will automatically pull your saved credentials from the Keychain and pre-fill the form for you, turning the text fields yellow.
While convenient, this is a massive security risk if you share your Mac with family members or coworkers. If you walk away from your desk, anyone can sit down, open Safari, navigate to your bank’s website, and Safari will happily autofill your username and password, granting them instant access to your financial accounts.
To ensure your accounts remain secure, you should disable Safari’s autofill feature and force yourself to authenticate (via Touch ID or your master password) before filling in credentials.
How to Turn Off Password Autofill in Safari
You must disable this feature within Safari’s internal preferences.
- Open the Safari browser on your Mac.
- Click on the word Safari in the top-left corner of the menu bar.
- Select Settings… (or Preferences) from the drop-down menu.
- Click on the AutoFill tab at the top of the window.
- You will see a list of items Safari is allowed to automatically fill in (Using info from my contacts, User names and passwords, Credit cards, Other forms).
- Uncheck the box next to User names and passwords.
- (Optional) You should also uncheck Credit cards to prevent anyone from using your saved payment information to make unauthorized purchases.
- Close the Settings window.
Safari will no longer automatically populate login fields. The next time you visit a website, the forms will be completely blank, requiring you to manually retrieve your password from Keychain or a third-party password manager.