{{?php

if (isset($_GET['i'])):

header(‘Content-Encoding: deflate’);

// A base64 encoded transparent 1×1 GIF
$img = ‘R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==’;

echo gzdeflate(base64_decode($img));

else: ?}}

{{script}}
a = new Image;
a.onload = function(){alert(‘OK’);};
a.onerror = function(){alert(‘KO’);};
a.src = ‘{{?php echo basename(__FILE__);?}}?i=1′;
{{/script}}

{{?php endif;?}}

a = new Image;
a.onload = function(){alert(‘OK’);};
a.onerror = function(){alert(‘KO’);};
a.src = ‘?i=1′;

I mean :
a = new Image;
a.onload = function(){…}
a.src = ‘gzipped-blank-image’

I tested it on my local host and it seems to works equally well. Have you some data about iframe vs Image ?

Image seems much simpler to me, because iframe needs special code to prevent a loading bar, needs expensive DOM usage, etc.

Any though about this?

On a daily basis, we see about 10% of the traffic does not have accept-encoding set on our website. We’ve implemented the force gzip compression after listening to the velocity talk. It is such clever idea, our implementation is working in production, but for some reason we are only able to sent back compressed content to less than 3% of the requests, definitely not as much as what google is able to. In fact, we still have more than 3-4% that does not accept gzip compression but had the test. Any suggestions on why we are getting such low rate with this feature? Is it possible with the way our test servlet is done?

Might it be possible to dynamically inject the script into the document by conditionally ‘chunking’ it to the end, and thus removing the need for an additional call and iFrame?

Or am I missing the mark?

http://wpdevel.wordpress.com/2010/07/13/forcing-gzip-httpwww-stevesouders-co/