Why do Flash videos like YouTube continue to buffer in Firefox Chrome Opera when you close the browser?

Answer 1

It is more likely to be an effect of the operating system and not the browser itself as the effect occurs with different browsers.

You do not specify your operating system. I'll answer based on my knowledge of what happens with Linux (and I guess something similar happens under Windows):

Flash videos are not handled by the browser itself but a plug-in; under Linux that plug-in runs as a separate process to the actual browser itself - a child process of the browser. When the browser is closed it can take "a while" for it to kill off its child processes and so even though the browser is closed, it hasn't finished tidying up its children and they may still run. Also, there could be a delay in the operating system itself in killing off the child processes (possibly with the child in an uninterruptable state whilst it is doing some of the buffering).

Assuming the buffering eventually ceases, then it is a delay that is annoying, but shouldn't be doing any harm.

With Linux you can always kill the plug-in process directly without killing the browser; with Firefox it just considers its child to have crashed.