Upl.co allows you to upload any sort of file. However while images are then displayed as such, all other files are simply made available for download. i.e. if you upload a video to Upl.co (or any other file-hosting site), you'll be given a link which you can send to others, so that they can then download the file (and subsequently play it with Windows Media Player, VLC or whatever other media player they use, on the own computer).
If you want to upload a video to a site in such a way that visitors to that site can immediately play it, you'll need to use a video-hosting site, with Youtube being the most obvious choice. (There are plenty of alternatives though, such as Vimeo and DailyMotion).