The Syncing Catastrophe
Google Chrome’s synchronization feature is designed to keep your browsing data—including passwords, history, and bookmarks—identical across all your devices signed into the same Google account. However, this synchronization relies on a central cloud database. Occasionally, due to a corrupted local profile, a conflicting third-party sync extension, or a brief server-side error during a merge process, Chrome’s sync engine can malfunction. When this happens, Chrome may interpret an empty local bookmark file as the “newest” state and push that state to the cloud, effectively automatically deleting your bookmarks across every device connected to your account.
Protecting Bookmarks and Halting the Sync Engine
If you notice bookmarks disappearing, you must immediately stop Google Chrome from automatically deleting the rest of your bookmarks by severing the connection to the flawed sync engine and restoring a local backup.
The very first step is to isolate the browser to prevent further deletion. Click your Profile picture in the top right corner of Chrome and click on Sync is on. Click the Turn off button to completely disable synchronization.
Next, you need to recover the lost data. Chrome automatically creates a single backup of your bookmarks file. Close Chrome completely. Open your file explorer. On Windows, navigate to C:\Users\[YourUsername]\AppData\Local\Google\Chrome\User Data\Default (On macOS, it’s ~/Library/Application Support/Google/Chrome/Default). Look for two files: Bookmarks and Bookmarks.bak. The `.bak` file is the backup from before the last sync error. Rename the current `Bookmarks` file to `Bookmarks.old`, and then rename `Bookmarks.bak` to simply `Bookmarks`.
Open Chrome; your bookmarks should be restored. Before turning Sync back on, go to your Google Dashboard online and select “Clear Data” under Chrome Sync to wipe the corrupted cloud data, forcing the servers to accept your newly restored local file as the master copy.