When comparing Screencast-O-Matic vs OBS, the Slant community recommends OBS for most people. In the question“What are the best screen recorders for Windows?” OBS is ranked 1st while Screencast-O-Matic is ranked 15th. The most important reason people chose OBS is:
You can record videos in formats such as mp4, flv, mkv, and more. You also have control over the bitrate used.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Includes basic video editing tools (pro)
The webapp includes video editing tools that allow cutting out and trimming around a section, zooming in & out, changing playback speed and adding transitions among other things.
Pro Web-based
Pro Scripts tool
Pro Webcam support
Pro Adjustable cursor size and optional click vizualizion
Pro Annotate video
Pro Full screen and area capture
Pro Records to many popular formats
You can record videos in formats such as mp4, flv, mkv, and more. You also have control over the bitrate used.
Pro Free and open source
No subscriptions or payments or licenses.
Pro Available for Linux, Mac, Windows
Pro Live streams
Can be used to stream.
Pro Fast
From the website: "GPU-based game capture for high performance game streaming."
Pro Extendable
OBS has an API allowing developers to create their own unique plugins, giving them and others complete control of their streaming experience.
Pro Encoding using H264 (x264) and AAC and file output to MP4 or FLV
Pro Unlimited number of scenes and sources
Cons
Con Restrictive free version
Free version is limited to creating up to 15 minute long, watermarked standard definition videos.
Con Requires installing a Java plugin
Con Recording a window will not record the menu bar, popup menus or child dialogs
Con Overkill for simple projects
Plus the interface is a bit intimidating.
Con Needs tutorial to get started
Otherwise it's hard to find out how to record a screen or window.