Web performance introduction boston web performance meetup

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  • 1. Boston Web Performance Meetup
  • 2. Why Web Performance?
    Faster sites boost conversion and help the bottom line
    Where is the evidence?
  • 3. Firefox
    1 second improvement on landing page drives 10 million Firefox downloads/year.
    Change all landing pages - 60 million additional downloads a year
  • 4. Bing
    2 second slowdown changed queries/user by -1.8% and revenue/user by -4.3%.
  • 5. http://www.stevesouders.com/blog/2009/07/27/wikia-fast-pages-retain-users/
  • 6. Google
    400 ms delay resulted in a -0.59% change in searches/user.
  • 7. Shopzilla
    Site overhaul shaved 5 seconds off of load time
    25% increase in page views
    7-12% increase in revenue
    50% reduction in hardware use
  • 8. http://velocityconference.blip.tv/file/2290648/
  • 9. WhatDoesLoad Time Mean?
    Two main pieces:
    End to End Latency
    Time between user request and the final byte of the response.
    Render Time
    Time between the last byte of the response and the Document Complete event.
    E2E Latency + Render Time = Page Load Time
    Time between a user clicking a link and the page becoming usable.
  • 10. Break It Down Further:
    DNS Lookup
    Time to map the domain name (www.cookware.com) to an IP address
    Initial Connection
    Time to open a connection to the server and get an acknowledgement
    Wait Time
    Time between initial connection and the first byte of the response (time it takes the server to “cook” the page).
    Content Download
    Time it takes to download the content that the server has finished creating
  • 11. Time to First Byte (TTFB)
    DNS Lookup + Initial Connection + Wait Time
    measurement of server/network performance
  • 12. What Affects Load Time?
    Do we attack E2E Latency or Render Time?
    80-90% of load time takes place in the browser
    Optimize Code
    Eliminate DB lookups
    Reduceload on server (perhapsthroughcaching)
  • 13. Client SideOptimizations
    Reduce # of CSS/JS includes
    Sprite images
    Reduce # of cookies, make cookies smaller
    Optimize JS code, reduce amount of it
    Load resources asynchronously
    Use a CDN
    GZIP components
    Minify CSS/JS
    Avoid redirects and 404’s
    Steve Souders: 14 rules for High Performance Web Sites
  • 14. ThreeBuckets for the Frontend
    Reduce the number of requests the browser has to make.
    Reduce overall page weight (KB on the wire).
    Make the browser do less work (executing code, painting, etc.).
  • 15. JavaScript canbe a HUGE problem
    Affects all threebuckets (requestit, downloadit, executeit).
    How do wefixit?
    Use a library (YUI, JQuery, etc.)
  • 16. http://www.pcmag.com/article2/0,2817,2364858,00.asp
  • 17. Tools/Books
    WebPagetest - http://www.webpagetest.org/
    Firebug - http://getfirebug.com/
    YSlow - http://developer.yahoo.com/yslow/
    PageSpeed - http://code.google.com/speed/page-speed/
    Dynatrace AJAX Edition - http://ajax.dynatrace.com/pages/
    High Performance Websites – Steve Souders
    EvenFasterWebsites – Steve Souders
    WebsiteOptimization – Andrew B. King (includes SEO)
  • 18. Conclusions
    Plenty of areas for improvement.
    First timers - easy to makehuge gains.
    There isalways more youcan do.
    Youruserswill love you (subconsciously in some cases).
    Let’s figure out ways to makewebsitesfaster!