I think this is the preference that you need to increase the "GoBack" context menu beyond the default of 10 items. browser.sessionstore.max_serialize_back

I believe that -1 makes to whatever the max stored "GoBack" pages for the tab are.

Based upon browser.sessionstore.max_serialize_forward which by default is -1 and older support answers I have found.

Thanks for the quick answer.

However, I set browser.sessionstore.max_serialize_back to 200, but I see only the last 15 entries when right-clicking the back key. i.e. it does not work.

The browser.sessionstore.max_serialize prefs apply to storing tab history data in sessionstore.jsonlz4.

I think that browser.sessionhistory.max_entries should still work.

• https://dxr.mozilla.org/mozilla-release/source/docshell/shistory/nsSHistory.cpp

It is of course possible that the Firefox version from the repositories that you use doesn't support this pref, so you can try to test this with the release from the Mozilla server.

I couldn't find the right-mouse-click action in nsSHistory.cpp, so I cannot tell what should happen.

What does happen if i right-click on the back button: I get a maximum of 15 entries, independent of the values on the preferences variables. When I use the 15th, i.e. most backward, and repeat the action, I get 8 more. If the intermediate pages are still accessible, I can go back to the initial page in several steps. But if an intermediate page is no longer available (i.e. login required) I am lost.

Its the size of the drop-down menu that seems to limit the number of entries. This size is 15 (and always was) in firefox.

However, there was an extension https://addons.mozilla.org/en-US/firefox/addon/back-forward-history-tweaks/ which extended the menu to much larger number of lines.

Unfortunately, this extension is no longer compatible with the latest firefox.

That maximum seems to be hard coded via MAX_HISTORY_MENU_ITEMS See FillHistoryMenu

• https://dxr.mozilla.org/mozilla-release/source/browser/base/content/browser.js