Before we start I will admit I've barely used any of these sites except for GoAnimate, so don't expect in depth reviews. The best I can do is give you my initial impression, ask you to watch their video and then go and try them all for yourself. I may do proper reviews at a future date.
GoAnimate
I'm a big supporter of GoAnimate which has been around since 2008 and allows you t create short, 2D cartoon animations using their library of thousands of characters, props, backgrounds and more. It's the leading site in its field and is being continuously refined with improvements.What makes GoAnimate stand out from the competition is that it can keep up with your growth as an animator and film maker. You can get some very professional looking results sticking with the content available but if you want to branch out and start animating your own characters and props using flash animation software you can. Import these back into GoAnimate and take advantage of how easy their studio is to use as well as still having access to their extensive library.
GoAnimate has evolved into a site promoted heavily for business explainer video creation but coming through it's initial hobby animator route it includes several character themes ideal for story telling including Anime, stick figures, Lil' Peepz, Politics and more.
For all round versatility and ease of use it can't be beaten.
Powtoon
Powtoon is best suited for explainer videos rather than story telling, unless you want to tell stories in a presentation style.Their studio is kind of like Microsoft Power Point with a cooler library of clip art and more features geared towards animated presentations. If you just want to create videos with graphics that fly in and out of each scene Powtoon is a great option that's a little less complex than GoAnimate.
Wideo
Much like Powtoon, Wideo is best suited to explainer videos. Its studio takes a similar approach to Powtoon using the familiar Power Point slide approach. Its library of pre-made props, characters and backgrounds isn't quite as extensive as Powtoons given it's a newer player in the field but what's there is pretty unique so you might choose Wideo on that basis alone.Moovly
Moovly is another recent entry to the animated video explainer market. Like the others it has a library of pre existing and animated content at your disposal. Creating animations using a more traditional approach of working around key frames on the studio's timeline.Just like Wideo its content library isn't that extensive yet but it does have a few unique styles that no other site really has. For example Moovly has the most convincing animated, whiteboard marker, drawing arm I've seen yet.
Video Rascal
If you have a thing for animated text explainer videos then Video Rascal may be for you. Although it only seems to have two templates it looks like there are plans for more. Creating a video is a very easy step by step process where the most difficulty you'll have is planning exactly how to layout your text so it looks good with the template you've chosen.You could probably do everything Video Rascal can do in GoAnimate, Powtoon, Wideo and Moovly but not anywhere near as quick. It's not that pretty just yet but with more templates and development it could be the go-to site for text based explainer animations.
Plotagon
Plotagon s a little different but familiar to those of you that may remember Xtranormal (which shut down earlier in 2013). In a nutshell it's 3D animation software that you can download and use to create animated short films just by typing in your script.
At the moment the quality of the finished animated movies make Xtranormal's platform look like it characters could act Shakespeare plays convincingly but I'm sure Plotagon will get better with further development.
Unfortunately Plotagon is a huge download (over 800MB) and I have to say I was pretty disappointed by its limitations. Again Xtranormal's desktop software, Slate, was a smaller download with greater abilities.
On the plus side the 3D is more realistic than Xtranormal and the interface is set out almost exactly like how you would format a screen play.
Currently it may be more useful as a pre-visualization tool, since the software chooses the optimum camera angles for you based on established film making principles. If you were making a live action film you could use the chosen camera angles as a guide for your live action camera placements.
Unfortunately Plotagon is a huge download (over 800MB) and I have to say I was pretty disappointed by its limitations. Again Xtranormal's desktop software, Slate, was a smaller download with greater abilities.
On the plus side the 3D is more realistic than Xtranormal and the interface is set out almost exactly like how you would format a screen play.
Currently it may be more useful as a pre-visualization tool, since the software chooses the optimum camera angles for you based on established film making principles. If you were making a live action film you could use the chosen camera angles as a guide for your live action camera placements.
I'm sure there are other sites out there - please let me know of any free sites within the comments and I may feature them in a future post.
Personally I would recommend GoAnimate to you every time but I would suggest you at least try the others, as I've become so accustomed to GoAnimate's studio that everything else tends to be quite limiting. If you're coming to these sites with no prior experience you may prefer some of the simpler studios in comparison to GoAnimate's highly evolved offering.