After uploading a video, Wistia encodes and compresses it to various sizes and formats like FLV and MP4, so viewers can have the best playback experience on any screen size, with any connection speed and on any device.
The following derivatives are created:
- 1280px wide HD 2,000 kbps
- 960px wide MD 1,000 kbps
- 640px wide SD 700 kbps
- iPhone 800 kbps
- HD iPhone (for iPad3) 1,200 kbps
The upload file size limit is up to 2GB per file.
If you are using other platform that do not encode the video to various formats like what Wistia does, you may face 2 problems... Viewers with slow internet connection cannot play the video smoothly and to solve the problem, you give them smaller file size videos, which leads to the next problem... viewers with better screens and connection will see very low quality videos.
My suggestion is to upload at the best quality and use a platform like Wistia or even YouTube, because of their down-encoding feature (side note: Vimeo is not very good at this feature. Udemy also recommends 1280x720 pixels, but their file size limit is 1GB per file.)