Slow motion video online

How to slow motion a video in real time online  ?

1. Upload  any video file (MP4, WebM, MKV)     
2. Hover the upload video icon   
3. Turn the mouse wheel  to change the video playing speed    🖱
4. In the beginning the speed decrease from 1 to 0 before to return to its original speed  =  1
5. Start to record  your video     
6. To slow down the video in real time as the video playing continue to turn the mouse wheel  until to reach the minimum speed = 0
7.   Pause your video     
8.  Download your video in slow motion