Andy King’s Web Page Analyzer is a smart tool for checking the speed of your site. It can detect whether or not your content is being served using gzip compression, and offers a number of suggestions for performance improvements. The most useful tip I’ve seen it offer is this one about external CSS and JavaScript files:

For external files, try to keep them less than 1160 bytes to fit within one higher-speed TCP-IP packet (or an approximate multiple thereof).

Watch out though: it seems that the analyzer doesn’t currently follow @import links in stylesheets, so it may under-report your included CSS files.

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  • zsepi

    it’s a great tool, however, it doesn’t report CSS image replacement techniques, thus the number of images used in the page and the total number of http requests displayed is not accurate

  • AlexW

    You can access it with a single click using the ‘Information/Speed Report’ option in the ‘Web Developer’ toolbar extension for FireFox too.

    Very handy.

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