'''UPDATE:''' ''This setting is no longer available in Firefox 119, unfortunately. A less convenient workaround can be found in:'' https://support.mozilla.org/en-US/questions/1429073#answer-1614190 ---- You can restore the orientation selector by making the following setting change. This overrides the ability of a web page to specify a paper size, which Firefox interprets as locking the orientation to the width/height stated by the page. (1) 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 I use this myself, I feel comfortable mentioning it.'' (2) In the search box in the page, type or paste '''layout.css.page-size.enabled''' and pause while the list is filtered (3) Double-click the preference to switch the value from true to false