This article explains how to import your bookmarks and other data to the Opera browser from another browser on your computer. This information applies to users running Opera on Linux, Mac OS X, macOS, and Windows operating systems.
How to Import and Export Passwords and Bookmarks in OperaGx
If you want to switch from another web browser to Opera, it only takes a few steps to transfer your bookmarks. Opera also gives you the option to transfer your browsing history, saved passwords, cookies, and other personal data. Here's how.
Open Opera and go to opera://settings/importData in the address/search bar.
A dropdown menu will show all supported browsers currently installed on your computer. Select the source browser with the items you want to import.