Bryan McQuade (Google), Richard Rabbat (Google, Inc.)

What’s Page Speed

  • FF/Firebug addon
  • Optimizes images, minifies JS, tells you what you should defer
  • 100K downloads in 10 days, 1000s of tweets, 100s of blog postings

How’d it start

  • wanted to help stop relearning lessons in new apps
  • keep you from unintended consequeces (e.g. vary header, squid won’t cache anything with params, etc.) Google map tiles used to have ? in URL; removing it gave huge boost in perf, huge reduction in requests
  • Sourced from many smart people on the web

Prioritizes according to importance/savings, gives easy way to see detailed info about any given rule, what’s violating it, docs on why and how of each rule

Defer loading JS as much as possible

  • Rule looks to see what’s not been invoked before OnLoad completes
  • Not enabled by default, has perf hit
  • Load multiple times in multiple scenarios; some JS is triggered in different

Inefficient CSS Selectors: based on David Hyatt’s post on inefficient selectors

Activity Panel

  • Show where most time is spent, where you should focus optimization
  • Shows DNS, network, connection, latency, data available for use, JS parse/exec, cache hits
  • Coming: paint events, screen snapshotting

BBC “has lots of room for optimization” gmail waterfall is hugely vertical!

Just released FF3.5 compatible version

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23 June 2009