The document discusses optimizing images and video for fast delivery on websites. It provides tips for improving image quality, format, sizing and lazy loading. For video, it discusses optimizing startup time by preloading strategically and balancing network usage. Testing tools mentioned include WebPageTest, HttpArchive, ImageMagick and SSIM. The goal is to make images and video both beautiful and fast loading.
3. 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
4. Large Downloads Induce Delays in Rendering
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
5. Images & Video make up 75% of Web Content
HTTPArchive mobile websites 15/02/18
68. Animated GIFs
Video Tags:
Video is not pre-loaded, will be last to download
<video loop autoplay 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>
https://calendar.perfplanet.com/2017/animated-gif-without-the-gif/
71. 71
Video
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
80. 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
90. Optimizing Video 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
92. Optimizing Video 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 192 KBPS
106. Contest – Win a €100 Amazon Gift Card
Optimize Images for Fast Page Load
Submit your entry by June 21 for a chance to win!
Code and tips: https://github.com/dougsillars/dougsillars.github.io
Entry form: http://bit.ly/FastImages
https://dougsillars.github.io