4. 0.5
0.6
0.7
0.8
0.9
Standing in Line Standing on the
edge of a virtual
cliff
Experiencing
Mobile Delays
Solving a Math
Problem
https://www.ericsson.com/res/docs/2016/mobility-report/emr-feb-2016-the-stress-of-steaming-delays.pdf
Stress
5. How Much Do Customers Hate Delays?
3s: 53% of Users Abandon Mobile Sites
500ms: 26% Frustration
8% Engagement
100ms: 1% Revenue Walmart & Amazon (Desktop 2001)
4% Mobile Users Throw Their Phones
https://www.doubleclickbygoogle.com/articles/mobile-speed-matters
http://bit.ly/mobileWebStress
http://www.globaldots.com/how-website-speed-affects-conversion-rates/
https://www.mobilejoomla.com/blog/172-responsive-design-vs-server-side-solutions-infographic.html
7. Cellular Networks Are High Latency Environments
• Connection Establishment 500-2500ms 50-250ms 1-10ms
• Round Trip Time (RTT) 200ms 100ms 8-50ms
3G 4G Wi-Fi
8. Today’s Goals
Test where your app/site is today
Common Tools
Learn best practices for speed
Learn from existing tests
See the results of performance
fixes
9. Testing Your Mobile Performance
Native Web
Free & Open Source Tools
Video Optimizer
https://developer.att.com/
Video-Optimizer
WebPageTest
https://www.webpagetest.org
https://webspeed.cloudinary.com
10. Testing With Video Optimizer
Run network traces on your
phone
1. Pick device
2. Collector type
3. Set network conditions
4. Decrypt HTTPS
5. Record screen?
6. Name
7. GO!
11. Video Optimizer
Video Optimizer
establishes a VPN
connection on Device
Collects all Traffic in/out
Device screen displayed
on your computer
Click Stop to end trace.
Files copied over to
computer for analysis.
38. Optimizing Content Delivery
Images
A random sample of 1,000 Twitter
images:
67% had room for optimization
(q_auto, f_auto)
Of 63,000 Twitter images, 1: 1000 >
50 KB (as high as 550KB)
https://dougsillars.com/2018/02/27/twitter-and-facebook-profile-images-already-optimized-or-is-
there-room-for-improvement/
50. Video Tags are slow:
Video is not pre-loaded, will be last to download
<video autoplay loop muted playsinline controls = "false” src="goats.mp4" />
Img tags are fast!
<picture>
<source type="video/mp4" srcset=”goats.mp4">
<source type="image/webp" srcset=”goats.webp">
<img src=”goats.gif">
</picture>
Optimizing Content Delivery
Animated GIFs
https://calendar.perfplanet.com/2017/animated-gif-without-the-gif/
52. 52
Buffer Rage
a state of uncontrollable fury or violent
anger induced by delayed or interrupted
streaming video content
http://www.ineoquest.com/press-releases/new-research-reveals-buffer-rage-as-techs-newest-epidemic
53. Video Startup Delay
After 2 seconds,
every additional
second corresponds
to 5.8% increase in
abandonment
https://www.akamai.com/kr/ko/multimedia/documents/technical-publication/video-stream-quality-impacts-viewer-behavior-inferring-causality-using-quasi-experimental-designs-technical-publication.pdf
56. Optimizing Content Delivery
What Leads to Startup Delay?
Manifest File:
List of Available
Streams
Player Chooses a Stream Stream Manifest:
List of Video Segments
Player Downloads
Segments into buffer
Video Plays
57. Optimizing Content Delivery
What Leads to Startup Delay?
#EXTM3U#
EXT-X-STREAM-INF:BANDWIDTH=8500000,RESOLUTION=1920x1080,sunflower1080/index1080.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=200000,RESOLUTION=416x234,sunflower234/index234.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=400000,RESOLUTION=480x270,sunflower270/index270.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=600000,RESOLUTION=640x360,sunflower360_600k/index360_600k.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1200000,RESOLUTION=640x360,sunflower360_1200k/index360_1200k.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=3500000,RESOLUTION=960x540,sunflower540/index540.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=5000000,RESOLUTION=1280x720,sunflower720_5000k/index720_5000k.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=6500000,RESOLUTION=1280x720,sunflower720_6500k/index720_6500k.m3u8
Example Manifest file:
58. Optimizing Content Delivery
Video Streaming
Manifest File:
List of Available
Streams
Player selects
8.5 MBPS stream Stream Manifest:
List of Video Segments
Buffer takes a long
time to fill
Video Does Not Play
Player immediately changes the
stream choice to 600KBPS
60. Optimizing Content Delivery
What Leads to Startup Delay?
#EXTM3U#
EXT-X-STREAM-INF:BANDWIDTH=8500000,RESOLUTION=1920x1080,sunflower1080/index1080.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=200000,RESOLUTION=416x234,sunflower234/index234.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=400000,RESOLUTION=480x270,sunflower270/index270.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=600000,RESOLUTION=640x360,sunflower360_600k/index360_600k.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=1200000,RESOLUTION=640x360,sunflower360_1200k/index360_1200k.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=3500000,RESOLUTION=960x540,sunflower540/index540.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=5000000,RESOLUTION=1280x720,sunflower720_5000k/index720_5000k.m3u8
#EXT-X-STREAM-INF:BANDWIDTH=6500000,RESOLUTION=1280x720,sunflower720_6500k/index720_6500k.m3u8
Example Manifest file:
8.5 MBPS is HIGH throughput for initial streaming
Best Practice: Pick middle throughput to balance startup time and quality
62. Optimizing Content Delivery
What Leads to Stalls?
Video Download
slower than playback,
so the video stalls
Buffer is filling, but
video has not resumed