YSlow 2.0 and ShowSlow 0.2 with updated beacon

Just a few days ago I wrote first version of ShowSlow and then released it Open Source.

But progress is unstoppable and Yahoo! released long-awaited YSlow 2.0 so it’s time for ShowSlow 0.2.

This means that I’m sitting down and analyzing Beacon parameters to make sure ShowSlow can collect data properly – so here’s the list of parameters that YSlow 2.0 is sending with the beacon (actual set of y* parameters depends on the profile used – ydefault sends them all):

• w – size of the page in bytes (v1 sent size in kilobytes)
• o – overall YSlow grade calculated for the profile used
• u – URL of the page tested
• r – total amount of requests with empty cache
• s – page identifier for yahoo pages (like yahoo music, sports, etc), blank on non-yahoo pages
• i – testing profile used:
  • ydefault – YSlow (V2)
  • yslow1 – Classic (V1)
  • yblog – Small Site or Blog
  • or custom profile’s title with dash-encoded spaces
• ynumreq – Make fewer HTTP requests
• ycdn – Use a Content Delivery Network (CDN)
• yexpires – Add Expires headers
• ycompress – Compress components with gzip
• ycsstop – Put CSS at top
• yjsbottom – Put JavaScript at bottom
• yexpressions – Avoid CSS expressions
• yexternal – Make JavaScript and CSS external
• ydns – Reduce DNS lookups
• yminify – Minify JavaScript and CSS
• yredirects – Avoid URL redirects
• ydupes – Remove duplicate JavaScript and CSS
• yetags – Configure entity tags (ETags)
• yxhr – Make AJAX cacheable
• yxhrmethod – Use GET for AJAX requests
• ymindom – Reduce the number of DOM elements
• yno404 – Avoid HTTP 404 (Not Found) error
• ymincookie – Reduce cookie size
• ycookiefree – Use cookie-free domains
• ynofilter – Avoid AlphaImageLoader filter
• yimgnoscale – Do not scale images in HTML
• yfavicon – Make favicon small and cacheable

Once again, to configure YSlow to send your data to a beacon, you need to set a couple configuration parameters on about:config page of your browser:

for YSlow 1.x

• extensions.firebug.yslow.beaconUrl = http://www.showslow.com/beacon/yslow/
• extensions.firebug.yslow.optinBeacon = true

for YSlow 2.x

• extensions.firebug.yslow.beaconUrl = http://www.showslow.com/beacon/yslow/
• extensions.firebug.yslow.optinBeacon = true

Where beacon URL is either public: http://www.showslow.com/beacon/yslow/ (your measurements will be shown to public so please make sure you’re OK with it before you use it) or private URL on your instance which you can get here: http://code.google.com/p/showslow/source/checkout.