Firefox browser allows to export your bookmarks into an HTML file that can later be used to import them into onother browser.
Exporting into HML File
1. Launch Firefox browser and click on the "hamburger" menu icon located in the top right corner of the window. A drop-down menu will appear.
2. Click on Library. You'll see this option near the top of the drop-down menu.
3. Click on Bookmarks. It's near the middle of the drop-down menu. A new menu with all of your Firefox bookmarks will open.
4. Click on Show All Bookmarks. You'll find this link in the bottom-left corner of the drop-down menu. Doing so opens a new window.
5. Click on Import and Backup. This option is the star-and-arrows icon at the top of the bookmarks library window. Clicking it prompts a drop-down menu. On Mac, click the Star icon at the top of the window.
6. Click on Export Bookmarks to HTML…. You'll find it near the bottom of the drop-down menu. A File Explorer (Windows) or Finder (Mac) window will open.
7. Enter a name for your bookmarks file. Type the name that you want to use for your bookmarks (e.g., "bookmarks 2018") into the "File name" or "Name" text box.
8. Select a save location. Click a folder on the left side of the window (e.g., Desktop). This is where your bookmarks file will be saved.
9. Click Save. It's in the bottom-right corner of the window. Doing so will save your bookmarks file under your chosen name in your selected save location.