Years ago, way back when the web first started to become universally popular–and I’m talking about popular with all demographics and not just geeks like me–there was the 30KB rule, and it was a cardinal sin to break it. The entire request, including your HTML, your images, and everything else your page contained, had to come in under 30 kilobytes. Most homes were surfing through the web on a 28.8kbps modem, which pulled 30KB in about 10 seconds. Beyond that 10 seconds, and your users were too bored, frustrated, or confused to wait another moment, and were off to pursue the next site in your WebRing. 30KB. That was the limit. It was universally accepted. And, save a few ransom notes on GeoCities, everyone followed it.
Whatever happened to the 30KB rule?
Today constantly see pages that are 100KB or more, and those are even compressed responses. Everyone is so caught up in broadband, and developing on their 100mbps LAN, that they forget about the little guy. What about grandma? My poor grandma still surfs the internet with a good ol’ 57.6kbps modem. And even if she could pull off that speed (US restrictions limit to 53, max) it would still take 20 seconds to yank that monster through the pipe. My poor grandma shouldn’t have to wait that long.
My company is making an application, and the primary audience is a bunch o’ satellite offices stuck in the 20th century. They plug in to a whopping dual ISDN which maxes out at a whopping 128kbps. That’s 16KB/sec for you young folk. That 100KB page will take 7 seconds to pull across the wire. Toss that fact in to the 10-second rule, and you only have 3 seconds to process the request. I have visions of little ones and zeros flying towards the light screaming “We’re not gonna make it!!”
Get a haircut. Trim those bushes. Bring that response size down a few K. Here’s a few ways to tame the beast:
“Remember that ViewState is evil.”
It adds a big, encrypted string to a hidden form variable in your HTML. However, this beast gets bigger with every web control that you have. Explicitly turn off viewstate on every control that does not use it, or better yet, turn of viewstate for the entire page. Of course, realize that the not-dot-net crowd is laughing at you while you do it.
Eliminate Comments in Release Code
“keep your comments to yourself.”
It is great to comment your code. It is fabulous. Every developer should bow to you if you comment your code, because not enough do it themselves. However, unless it is compiled code or in code-behind that isn’t sent to the client, it has to go. You can keep your comments in the version stored in SVN, VSS, or whatever your favorite source control tool is, but your release code should contain no client-side comments. Your client doesn’t read them, their browser doesn’t care about them, and all it does is slow everything down, so give them the axe. Your network administrator will love you for it, too.
“Phenomenal, Artistic Imagery, Itty-Bitty Living Space.”
Compress your images. Get them as small as your image editor can get them (small: file size, not small: pixel size) without degrading the image beyond acceptable levels. And if you use a GIF, lower the number of colors (which will lower the number of bytes). When your images get smaller, people get happy.
“One Program: One Line of Code.”
This is a cheap trick to squeeze out those last few bytes. If you have a news article that’s 9 pages long, open it up in notepad and turn off word-wrap, it becomes one big long line that stretches out forever and is impossible to read. But, your browser could care less. Take out all of the horizontal white space that you use to make your code readable, and then take out all the line breaks to make your HTML one big line, and your browser couldn’t tell the difference. However, you just chopped a few more bits.
“GZip it, and GZip it good.”
If all else fails, and you’ve gotten your pages as whittled down as you can, and they are still big, compress it. Then again, even if they are small, compress it. It will add a few more CPU cycles on both ends to compress and decompress the response, but the time lost is greatly countered by the time saved in data transfer. Typical compression is around 40%, which takes that 100KB file down to 60KB, and saves my grandma nearly 8 seconds. She’ll give you a kiss and squeeze your cheeks for that one.