You can look on the Add-ons website for a suitable extension.

• https://addons.mozilla.org/en-US/firefox/search/?type=extension&q=vertical%20tabs

Thanks cor-el. I think native integration will still be better. Right now to use many of the extensions, you need to jump major hoops to edit the CSS of firefox to stop the horizontal tabs displaying. There is obvious risk that less-technical users can't achieve this or won't be able to regain their horizontal tabs if the extension breaks for whatever reason. Also, if you read the forums you'll see people are very unhappy with many of the extensions, citing overcomplexity and a lack of user-friendliness. Hoping I can get access to some type of feature-request portal since the previous one seems to be defunct.

Hi,

If you want to leave feedback for developers, you can go to the Firefox Help menu and select Share ideas and feedback…. Alternatively, you can use this link. Your feedback gets collected by a team of people who read it and gather data about the most common issues.

You can also file a bug report or feature request. See File a bug report or feature request for Mozilla products for details.