To import Opera GX to Firefox, you need to transfer your bookmarks, passwords, history, and other personal data from Opera GX into Firefox, not install a theme or extension. Firefox includes a built-in Import Wizard that handles this directly from an installed Opera GX browser, and there’s also an HTML file method for bookmarks if you prefer more control.
How to import Opera GX to Firefox using the import wizard
Firefox’s direct import feature reads data straight from an installed Opera GX browser on the same computer, so you can move your saved logins, bookmarks, browsing history, and preferences without leaving the browser. This is the fastest way to import Opera GX to Firefox because it preserves the structure of your data and requires no manual file handling.
- Open Firefox and click the menu button (three horizontal lines) in the top-right corner.
- Select Settings from the dropdown menu.
- In the General or Account and sync panel, scroll to the Import browser data section and click Import Data.
- The Firefox Import Wizard will open. From the list of source browsers, select Opera (which includes Opera GX) and click Next.
- Choose the data types you want to import, such as bookmarks, saved logins and passwords, browsing history, and preferences, then click Import.
- After the process completes, click Done to close the wizard.
Your selected data now lives inside Firefox. You can verify that bookmarks appear in the Library and that passwords are stored in the saved logins section. If you only need bookmarks and prefer not to touch the wizard, the HTML method below gives you an alternative that works even if Opera GX is not installed on the same machine.
Importing bookmarks from an HTML file
If you want to import Opera GX to Firefox without using the wizard, or if you need to move bookmarks from another computer, exporting them as an HTML file is a reliable fallback. This method also lets you review and clean up your bookmark list before it lands in Firefox, which is especially useful if you have a large collection.
- Select Bookmarks > Bookmark Manager (or press Ctrl+Shift+O).
- In the Bookmark Manager, click the three-dot menu or the import/export icon, then choose Export bookmarks as HTML.
- Save the file to a location you can find easily, like your Desktop.
- Open Firefox and press Ctrl+Shift+O (or click the menu button, then Bookmarks > Manage bookmarks) to open the Library window.
- In the Library, click Import and Backup and select Import Bookmarks from HTML….
- Navigate to the HTML file you exported from Opera GX, select it, and click Open.
Firefox will add the bookmarks into a folder named after the import date or “From Opera GX,” depending on your version. You can then drag them into your preferred bookmark folders in the Library. This method avoids the wizard entirely, but it only moves bookmarks, passwords and history are not included in an HTML export.
Managing your imported data
After you import Opera GX to Firefox, the most common issue is duplicate bookmarks, especially if you’ve run the import more than once or used both the wizard and the HTML method. To clean this up, open the Library (Ctrl+Shift+O), click Import and Backup, and select Show All Bookmarks. Look for folders like “From Opera GX” or “Imported on [date],” then manually delete any duplicates or merge them into your existing structure. Firefox does not automatically deduplicate, so a quick review saves you from a cluttered bookmark bar.
For passwords, confirm they transferred successfully by going to Firefox’s Settings, then Privacy & Security > Saved Logins. You should see your Opera GX logins listed there. If any are missing, you can re-run the wizard and select only the passwords option, or use a CSV file export from Opera GX and import it via Firefox’s migration wizard. If something didn’t come through, repeat the wizard and select the specific data type you need, since Firefox allows you to re-import without duplicating already-transferred items.
