Is there an app to change my portrait video to landscape?

I forgot to hold my phone sideways when I took a video on my iphone. Is there an app to change the orientation?

I can understand wanting to take a portrait photo, but not a portrait video. Just about every device that you would want to play a video back on is landscape in format. Why would you want to display a video the other way round?

You wouldn't be able to convert it without chopping out a huge amount on the left and right side of the video. If you just turn it sideways you would have to watch it with your head turned round!

No… Not that I know of.

An "app"? Maybe… Like a video editor on your computer. Even some phones have a video editor available (but since we don't know which phone you are using, we can't tell you what video editor might be available).

Get the video to the computer, Get the video file into a file type and format the video editor can deal with. Open the video file in the video editor. Rotate. Save. Export/share/render.