I'm using Flex 4 and the Spark VideoPlayer. I'm creating an application where you switch between several videos. I noticed that the browser memory usage increases significantly when changing videos and never releases the memory. I ran tests where the video is being served over a content delivery network that has Flash Media Server, so the content shouldn't be caching in the browser. I profiled my Flex application and the memory usage increases slightly when changing videos. I think that is attributed to this bug: https://bugs.adobe.com/jira/browse/SDK-25785. However, my browser memory usage increases about 20MB when changing videos. The video file I used to test is an mp4 file that is about 3MB in size. I tried testing using a small video (about 300Kb) and noticed an increase of about 5MB in browser memory usage every time I replayed it. So it looks like it's based on the video file size. I was testing on Firefox and noticed the same results in Chrome. Any idea why the browser memory usage would increase so much every time the video is loaded?