Chris Bailey of Adwerx
100ms or less is instantaneous.
100ms of latency costs 1% of sales according to Amazon.
Anatomy of a transaction
Page load time
47% of people expect a web page to load in 2 seconds or less.
40% will abandon if takes more than 3 seconds to load.
Start render time
User starts to feel in control when page starts to render.
Time to first byte
Average size of page is 2.2MB, including HTML, stylesheets, images, etc.
Doubled since 2010. Avg. size in 2005 320kB.
Synthetic vs. Real-User Metrics (RUM)
Synthetic can be measured using real browsers in AWS.
RUM can be very skewed based on user connection types.
"Using WebPageTest" book from O'Reilly
Displays real-user metrics
New Relic Browser
- Real-user metrics
- Splits time into web app, network, browser
- Can view entire session activity for random users
Chrome dev tols
window.performance in JS console
New Relic APM
Monitor performance of web app server
- From Yahoo
Google PageSpeed Insights
- Similar to YSlow
80% of effect com from 20% of causes
What worked for Adwerx
Switch CDN from Amazon CloudFront to Fastly
- Home page from 3.2MB to 2.6MB
8-9s down to ~6s per load with minimal changes, assistance from Fastly engineer.