File compression before downloading via http

Question

Is it possible to compress data sent from the client’s browser (file download) to the server?

Flash, silverlight and other technologies are fine!

Answer 1

Browsers never compress downloaded data because they don’t know if the server supports it.

Downloaded content may be compressed because the Accept-Encoding request header allows the browser to indicate to the server that it supports compressed content. Unfortunately, there is no equivalent protocol that works differently and allows the server to tell the browser that it supports compression.

If you have control over the server and the client (for example, using silverlight, flash), you can use the compressed request bodies.

Answer 2

There is a library for Silverlight called Xceed, which, among other things, "Allows you to compress data as it loads." However, this is not free. I believe that this can only be done using technologies such as Flash or Silverlight, and not initially in the browser.

I do not agree with the aforementioned poster that browsers do this automatically, and I believe that this happens only with standard HTML / CSS / Text files, and only if the server and browser have compression (gzip, deflate).