Published on May 25, 2012
Speed is Essential for aGreat Web Experience@andydaviesPort 80 (#p80N)May 2012 http://www.ﬂickr.com/photos/44442915@N00/5214810596
But sometimes other concerns take priority... http://www.ﬂickr.com/photos/randomidea/247994072
“Are we there yet?” http://www.ﬂickr.com/photos/sharynmorrow/643126727
Our perception of response time Instant Seamless Yawn!100ms 1s 10s Response Time in Man-computer Conversational Transactions Robert B. Miller, 1968
Our perception of response time Instant Seamless Yawn!100ms 1s 10s 3s - Recommended 7s - Fortune 500 Load Time Average (2010) Response Time in Man-computer Conversational Transactions Robert B. Miller, 1968
“50% more concentration when using badly performing web sites” Foviance http://www.ﬂickr.com/photos/yourdon/3366991042
Effect of delay on abandonment rate... Abandonment rate over 200+ sites / 177+ million page views over 2 weeks - http://www.measureworks.nl / Gomez
Google conducted an experiment +400ms -0.6%
Bing did some experiments too +1s $/ - 2.8% +
Shopzilla cut page load time by 5 seconds! +12% +25% -50% $$$ http://velocityconf.com/velocity2009/public/schedule/detail/7709
Measuring page load time...
Measure Real Users’ Experience 27% 24%Visitors (%) 13% 8% 8% 6% 6% 3% 3% 2% 1% 1 2 3 4 5 6 7 8 9 10 > 10 Load Time (s)
Measuring Real Users - Google AnalyticsRelies on Navigation Timing API, can add extra timing calls to page
Measuring Real Users - Torbit Insight
Measuring Real Users - Torbit Insight (Check out at Log Normal too)
Measuring Real Users - New Relic
Waterfall for bbc.co.uk/news
Bigger, Faster Servers? http://www.ﬂickr.com/photos/br1dotcom/4297736794
80% plus of page load time is on front-end Backend news.bbc.co.uk Frontend ebay.co.ukdebenhams.co.uk direct.gov.uk amazon.co.uk mumsnet.com guardian.co.uk 0 1.25 2.5 3.75 5 Measured on residential ADSL line using Chrome 19
Fix slow server responses ﬁrst 4 seconds!
Bandwidth (often) isn’t the bottleneck2.01.51.00.5 0s 5s 10s news.bbc.co.uk tested via webpagetest.org throttled at 1.5Mbps (bursts over 1.5Mbps are artifact of testing)
Minimum round trips to download a ﬁle (TCP Segments)285kB214kB143kB 71kB Size 1 2 3 4 5 6 7 8 9 10 11 Round Trips TCP and the Lower Bound of Web Performance John Rauser
Speeding Things Up - The Basics CSS at top Compress Consilidate Minify Reduce Requests Cache Forever JS at bottom
Proportion of URLs that can be compressed ☺ ☹ http://zoompf.com/blog/2012/05/http-compression-use-by-alexa-top-1000
What’s the web made of? Images Scripts Stylesheets HTML Flash Other Composition of ‘average’ web page via httparchive.org
Bitmapped Images JPEG PNG GIF Optimise, Optimise, Optimise! (jpegmini, pngmini, Smush.it, ImageOptim, Gifsicle etc.)
CSS Sprites + background-position: -408px 0; width: 128px; height: 128px; =
Data-URIs<img width="128" height="128"src="data:image/PNG;base64,iVBORw0KGgoAAAANSUhEUgAAAIAA ... =GAA39eV7u4AAAAAElFTkSuQ" /> Should be served with GZIP
New Devices, New Challenges... 2 x Resolution = 4 x Pixels! http://www.ﬂickr.com/photos/roopaw/6985954465
Look Ma, No Images!border-radius: 20px;background: linear-gradient(left, #f06, #ff0); Watch mobile performance. Remember vendor preﬁxes!
Vector Graphics FTW? SVG: 12 KB vs PNG: 86KB
What about icon / pictogram fonts? ★ ★ ☆ ☆ ♥ ♥ ☁ ☁ Heydings by Heydon Works “Bog Standard Font”
display:none - still downloads images “#p80n you do get adverts on the smashingmag site on smaller viewports. They just hideously display:none; so you still down load them :-/” @sturobson
Don’t forget about favicon.ico 1.4 seconds for favicon!
Don’t forget about favicon.ico 1.4 seconds for favicon! <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
Don’t block the browser... http://www.ﬂickr.com/photos/barteko/6128499314
news.bbcimg.co.uk static.bbc.co.ukBrowsers can download resources in parallel
But Sometimes... The Waterfall of Doom! 2 seconds! (nearly)
Social buttons break... http://bit.ly/yRjX63
Social buttons break... http://bit.ly/yRjX63
Argh... My brain hurts! http://www.ﬂickr.com/photos/corneveaux/3248566797
Don’t have to do it all by hand http://www.ﬂickr.com/photos/simeon_barkas/2557059247
Performance isn’t just for Christmas Measure Optimise Analyse
@andydavies firstname.lastname@example.org://www.slideshare.net/andydavies http://www.ﬂickr.com/photos/auntiep/5024494612
CreditsAll photographs copyright original owners on ﬂickr.comFollowing pictograms courtesy of The Noun Project
Slides available at http://www.slideshare.net/AndyDavies/... NCC Group Presentation by Andy Davies on Speed is essential for a great web ...
... most reliable mobile web experience as the stakes—and ... Speed is essential for a great web experience ... "Web Performance, Why it ...
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With the new MacBook comes a whole new way to experience a ... you can connect to the web, ... It also comes with a collection of great apps for ...
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Collaboration across disciplines is essential to remaining ... If you provide a great experience, ... If only "UX" were limited to building web sites and ...
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