Few weeks ago with some liipers we registered to watch the web performance summit. This is a conference taking place on the web, which is nice as you don't have to physically travel to some remote location to attend the talks. The downside of it being obviously that you cannot meet and talk to people.
The conference runs for a full day (8 hours worth of presentations) and can be viewed live or later on. We didn't manage to stay up till the end of it as the conference was schedule for happening during American day time, which more or less translate to European evening.
Anyway we have already watched a good part of it and another viewing session is about to be schedule soon for those who couldn't attend it.
In general the conference was interesting and the talkers made a good job at presenting their content. I personally found the following talks of particular interest.
Achieving Better Image Optimization by Billy Hoffman
This talk is about how you can gain performance by properly handling you image resources. Billy goes in every detail to explain us which file format to choose and what compression options are available. In most case he claims that you can reduce your images size by a significant percentage without losing any [viewable] quality.
It is known since some time that compressing your website's assets (js, css, html) is a good thing to do in order to make it faster. What Billy is pointing at, is that, although it is good to compress your css and js and you should still doing it, it would be much more efficient to start compressing your images as they usually represent the biggest part of the bandwidth used to transmit data from your webserver to your the web clients. Usually images account for about 75% of your page weight so reducing this amount will have a bigger impact than reducing the 25% page weight of the other assets.
Then a good part of the talk is dedicated to how to reduce your image size while keeping as much quality as possible. I would recommend any of you to have a look at this talk or at the slides. Even if you cannot remember all details just being aware of those concerns will be of great help to make your site faster.
Improving Request and Response Headers by Kyle Simpson
In this talk Kyle Simpson talks about all those request/response headers that are of little value and can be sometime a waste of bandwidth. Of course anyone would argue that headers are usually small enough to be insignificant compared to the html and images of a web page. But Kyle points out that those extra bytes sent and received can represent a large bandwidth consumption when we are talking about a website with a large audience and many thousand of HTTP requests per day.
One of the biggest waste is due to cookies. This header can get [relatively] big on many website (on average around 200 and 400 bytes). Although every one knows the usefulness of cookie, it is rarely acknowledge that they are useless in 80%, if not more, of your requests. Can anyone tell me what use of cookie can be done when getting a css file or an jpeg image? Bear in mind that the cookies are also sent back with the response, doubling the uselessness of those couple of hundred bytes in such cases.
The solution to this is simply to have your static assets served from another domain than your website. Being on another domain the browser won't send those cookie information and you will save some bandwidth and increase your website speed.
You can have a look here to find a written down version of what Kyle talked about in this talk.
Performance in Business Terms by Joshua Bixby
This talk from Joshua Bixby somehow echoed the keynote I have seen at Phpday 2011 by Steve Souders. In both of them, one of the main argument is that performance is your website's number 1 feature. This is almost contradictory to the popular believe that speed is not important as long as you have a long list of feature.
Well apparently this is wrong. Speed is important and to such an extent that the revenue you generate from your website depends on it. Many studies done by different website and organization (including amazon.com) found a strong correlation between your website's speed and the cash it generates. This is mostly true for merchant website but not only. To make it more general: if your website is fast then users will have pleasure to use and so will use it more. And the more they use it, the better it is. This will trigger more sells, more ad print, and more widespread awareness of your website and so on. So all in all it is good whatever your site business is.
To wrap up I believe that we should get more awareness about those simple things that can make your website faster as we all benefit from it, our users are happier, we spare on resources (bandwidth, storage, electrical) and we have a chance to increase our business (in the most general sense of it).