[thresh]

It's all fun and games until we realize our web designers put a four megabyte jpeg on the index page.

[Sami_Lehtinen]

What, JPEG? I thought real designers prefer high quality content and use 20 megabyte PNGs. (been there, done that)

[benhoyt]

I think this is a really good point. While I like the article's focus on depth, and thinking about the small stuff is important, saving a few bytes on headers is going to be blown out of the water by all the images, JS, CSS, and 3rd-party pixels being loaded. "Profile before optimizing" applies here too.

[mcguire]

1. Images are transferred once, not with every request.

2. Most requests and many responses are all or mostly headers.

3. Intermediaries.

4. Header compression is at the protocol level; if it's done wrong, the best js/css/whatever policy can't do anything to improve it.

[youngtaff]

But I bet you most people will never profile this.

We have a tendency to focus on page size but what really matters is the user experience.

For all the advice of putting making sure the first 15KB of a page counts, inlining critical styles etc., it that response has 4KB of headers e.g. large cookies, then all of a sudden you've got 11KB!

[udp]

The 4 MB JPEG would be downloaded, though, while the headers would be uploaded. Consumer internet has terrible upload speeds in general.

[dcbadacd]

Given today's screen resolution, anything less would probably look horrible.

[seanwilson]

Use SVG. Infinite detail. Doesn't work for photos though.