The icon is misleading. I thought it was a means to have a split view, which I would love. By showing the '2nd' window in a side view you cannot compare the two views, since for most sites the phone interface kicks in, due to the prevalent responsive design. (a developer feature - not a user feature - which is quite confusing to most users)

It's a great add-on. It can open bookmarks and sites on sidebar as either mobile or desktop version.

Funciona como queria, obrigado.

Хорошо бы было если бы в открывающейся вкладке была строка, позволяющая открывать сайты напрямую, а не через журнал.

와, 진짜 최고입니다. 사이드 페이지에 열어놓은 탭을 다른 탭에서도 항상 볼 수 있는데 정말 유용하네요.

非常好用,希望能增加 同时滚动功能,add sync scroll

Still has many problems.

it is great extension. Can not find nothing like that in Chrome

I had high hopes for this but in its current state, I rarely use it (and just now disabled it). Firefox needs a split screen mode like Vivaldi, where tabs can be split into 2/3/4 screens. Let's start with 2 for now but allow us to remain in our session and not log us out. Let the page not reload just for opening it in a split view. This actually signs you out of the website (the one in the side view). It reloads the tab when you add it to the side view. It's all over the place when it comes to websites where you're signed in.
It's really a very bad implementation and it's clear that care is not given to this add-on, which is unfortunate.

Allow us to split screen an .html file (that I open from my Desktop, which opens in Firefox) with a on-the-Internet tab.

I really want a real split screen add-on, one that also would let us resize to our heart's content and not be limited as we are now. One that displays the tab without reloading, without signing us out, without a new cookie or whatnot. Look at Vivaldi's Page Tiling and imitate that, that's all!

Edit: Use Tile Tab add-on, it's good enough for now but not like Vivaldi's implementation, which is the best.

Very useful addon but better if it can bookmark the websites for open.

This works as advertised. You know how great a complement this statement is in these dark times!

I have two suggestions:

1. As practically all other folks here are demanding, the sidebar must be wider. If this is because Side View uses the built-in side view pane in Firefox, please, if at all possible, implement your own side pane and make it wider.
In case that's possible, why not more than one side panes simutaneously? Keeping two sidebars at each side would be very nice.

2. The Side View icon on the quick menu that appears at the top right corner by default. Currently its only real function is to switch between mobile/desktop view.
Please add that command in the context menus. Currently it has only one item (Open in sidebar), please change it to something like 'Open as Desktop/Mobile Site in sidebar' - so that if you click an empty space or tab, you could also choose how it will load. Then we could unclutter the quick toolbar if we choose to without sacrifice. Keeping track of sidebar-only visit history can be nice to some people, but I find it not very crucial.

very useful (i like it to keep the todolist or notes in sideview).

wishlist:
+ it would be nice to be able to drag tabs to sideview.
+ and in some cases a second (or even more) sideview can be useful, i.e. to use some columns to compare mobile views of sites or to view trello, notes, mobile site & desktop site together