The Forced Profile Link
Google Chrome strongly encourages tying your browsing activity to a Google Account. By default, Chrome employs a feature called “Allow Chrome sign-in.” This means that if you simply log into Gmail or YouTube on the web to check your messages, Chrome automatically assumes you also want to log the entire browser profile into that account. It links your browsing history, bookmarks, and settings to that Google Account, and changes your browser avatar in the top right corner. If you share a computer with family, or use a personal computer for occasional work emails, this automatic browser-level sign-in blends your personal and professional data in highly undesirable ways.
Severing the Browser-to-Web Link
To keep your web logins strictly separate from your browser profile and stop Google Chrome from automatically signing you into the browser when you check your email, you must disable the global sign-in linkage.
Open Google Chrome. Click the three vertical dots in the top-right corner and select Settings. In the left-hand navigation sidebar, click on You and Google. In the main panel, click on Sync and Google services. Scroll down this page until you find the section labelled “Other Google services.” Look for the toggle switch next to Allow Chrome sign-in. By default, this is turned on. Click the toggle to turn it Off. A prompt will appear stating you must restart the browser for the change to take effect. Click the Relaunch button. Now, you can log into any Google website (like Docs or Gmail) without Chrome automatically adopting that identity for the whole browser.