Is your new Firefox connected to your Mozilla account? If so, try opening the Synced tabs sidebar. For example, you can press Ctrl+B to open the Bookmarks sidebar, then click Bookmarks and select the Synced Tabs sidebar. If you are lucky, they will be listed there, too. Now, how to migrate them. If you right-click a device name, it does have "Open All in Tabs" but for 100 tabs, this is going to be pretty challenging. Individual tabs have a right-click > Bookmark Tab... option but that's a lot of clicking. As an alternative, you can archive all of the Synced Tabs to an HTML document in the classic bookmarks.html format, using a browser console script. This isn't officially supported, but if you want to try it, here's how: (1) One-time setup to enable the command line in the Browser Console ''(A)'' In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future. Since we have had this setting for a long time and I use it myself, I feel comfortable mentioning it.'' ''(B)'' In the search box in the page, type or paste '''devtools.chrome.enabled''' and pause while the list is filtered ''(C)'' Double-click the preference (or click the toggle button on the right end of the row) to switch the value from false to true (2) Open the Browser Console using Ctrl+Shift+J (3) In the command line at the bottom or bottom left, paste the script from https://gist.github.com/jscher2000/b7094b3e74b95e5ba9c26f1f685bda6e (4) If "Run" appears above the script, click Run. Otherwise, press Enter to execute the script.