A presentation at JSConf Budapest in in Budapest, Hungary by Denys Mishunov
Why PERF RMANCE Matters? DENYS MISHUNOV · Digital Garden AS · @mishunov
Conversions 1 SECOND PERFORMANCE IMPROVEMENT http://goo.gl/E030E 2
Conversions 1 SECOND PERFORMANCE IMPROVEMENT http://goo.gl/E030E $482.2 billion
4,6 %
5 %
7,9 %
http://goo.gl/JnXZ2x
33.3 million uniques http://goo.gl/JnXZ2x
112.6 million views http://goo.gl/JnXZ2x
PERF RMANCE is not MATHEMATICS
PERF RMANCE is PERCEPTION
https://www.youtube.com/watch?v=d5_6yHixpsQ
WEBER-FECHNER LAW JND (just noticeable difference)
20% RULE EVENT
20% RULE EVENT 20%
NOTICEABLE = != MEANINGFUL
Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio.
Duis autem vel eum iriure dolor in hendrerit in vulputate velit esse molestie consequat, vel illum dolore eu feugiat nulla facilisis at vero eros et accumsan et iusto odio.
ACTIVE Boy, am I busy! PASSIVE
ACTIVE Boy, am I busy! PASSIVE
PREEMPTIVE START ПРОЦЕСС EVENT EVENT ACTIVE PHASE EVENT
PRELOAD TOP HITS mobile Safari Settings / Safari / Preload Top Hits
EARLY COMPLETION ПРОЦЕСС EVENT EVENT EVENT ACTIVE PHASE
PASSIVE PHASE
PASSIVE PHASE
ACTIVE PHASE
goo.gl/JnXZ2x
goo.gl/JnXZ2x
PASSIVE PHASE goo.gl/JnXZ2x ACTIVE PHASE
compress
async compress
workers
“ The perception of performance is just as effective as actual performance in many cases ”
THANK YOU DENYS MISHUNOV · Digital Garden AS · @mishunov
Load a page in less than a second; reduce the number of server requests; keep your CSS and JS merged and compressed to keep them under 50 kilobytes” – these are just a few among technical solutions and recommendations we are getting in the industry to tackle performance issues. But there is one catch – your users don’t care about absolute values in kilobytes, milliseconds and number of requests.
Performance is not about Mathematics. Performance is about Perception. Perception is what makes a site with a very few requests nevertheless feel slow, while a site that delivers search results during tens of seconds can feel fast enough for your user. User’s perception of your website’s speed is the only true performance measure.
This talk is about perception, neuroscience and psychology. The time is ripe to understand performance from the user’s perspective.
for free. You
can too.