There are lots of excellent tools to help web developers optimise their websites.

Here are two simple things you have no excuse for overlooking on your next project.

HTML, XML, Javascript and CSS files

One of the easiest ways to speed up a website (often to a surprising degree) is to turn on compression of plaintext content through facilities like mod_deflate or the Gzip Module.

Here's the Apache configuration file I normally use:

AddOutputFilterByType DEFLATE text/html text/plain text/css text/javascript text/xml application/x-javascript application/javascript  
BrowserMatch ^Mozilla/4 gzip-only-text/html  
BrowserMatch "MSIE 6" no-gzip dont-vary  
BrowserMatch ^Mozilla/4\.0[678] no-gzip  

Images

As far as images go, the following tools will reduce file sizes through lossless compression (i.e. with no visual changes at all):

• gifsicle -O2 -b image.gif
• jpegoptim -p --strip-all image.jpg
• optipng -o7 -q image.png

(An alternative to optipng is pngcrush.)

Note that the --strip-all argument to jpegoptim will remove any EXIF/comments tags that may be present.