Doug Sillars presented four simple optimizations for delivering fast and beautiful images and video on mobile: 1) reduce image quality, 2) use optimized formats like WebP and SVG, 3) size images appropriately, and 4) lazy load images below the fold. He demonstrated how these techniques can significantly reduce page load times and data usage. Sillars also discussed best practices for video delivery and alternatives to animated GIFs that can reduce file sizes substantially. Throughout, he provided real-world examples and tools to help optimize multimedia content for mobile performance.
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. 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
6. Images make up 50% of Web Content
HTTPArchive mobile websites 15/02/18
28. Image Formats – Average Size
HTTPArchive mobile websites 15/02/18
29. Image Formats – Average Size
HTTPArchive mobile websites 15/02/18
30. Scalable Vector Graphics (SVG)
Images drawn as shapes
infinitely scalable
XML - Can be added inline to HTML document
https://gist.github.com/hail2u/2884613?short_path=66a60ff
31. Scalable Vector Graphics (SVG)
Images drawn as shapes
infinitely scalable
XML - Can be added inline to HTML document
https://gist.github.com/hail2u/2884613?short_path=66a60ff
76. Animated GIFs
“The Graphics Interchange Format is not
intended as a platform for animation, even
though it can be done in a limited way.”
-GIF89a Specification
https://www.w3.org/Graphics/GIF/spec-gif89a.txt
89. Video Background
Video (as Downloaded): 5.3 MB
Video 5 MB
Audio 250 KB 5% of file
Best Practice:
To save bandwidth, remove the audio stream from videos that
are played silently.
112. Addendum 2: Network Info
// Network type that browser uses
navigator.connection.type;
// Effective bandwidth estimate
navigator.connection.downlink
// Effective round-trip time estimate
navigator.connection.rtt
// Upper bound on the downlink speed of the first network hop
navigator.connection.downlinkMax
113. Addendum 2: Network Info
// Network type that browser uses
navigator.connection.type;
// Effective bandwidth estimate
navigator.connection.downlink
// Effective round-trip time estimate
navigator.connection.rtt
// Upper bound on the downlink speed of the first network hop
navigator.connection.downlinkMax
500 KBPS
114. Addendum 3: Base 64 Encoding
Images embedded as Base64 in your HTML/CSS/JS
• Fewer Requests
• Images Now Block Rendering of Page
• Images are 20-30% larger
• Caching is limited
• Difficult to reference more than once
https://calendar.perfplanet.com/2018/performance-anti-patterns-base64-encoding/
115. Addendum 3: Base 64 Encoding
• 91KB CSS Shared as University Template
• 48KB is SVG
• Never Appears on Any Page
Departments, colleges and other units of
the University of Nebraska–Lincoln should
use the Nebraska N as a main identifier,
not the University seal, on all publications,
invitations, websites and other electronic
media.
https://unlcms.unl.edu/wdn/templates_4.1/css/all.css?dep=4.1.36
116. Addendum 3: Base 64 Encoding
https://cdn.glowing.com/generated/css/base.474240e8485dbff13fd3652d24ef83bc.css
117. Conclusion
Optimize Image:
Quality
Format
Sizing
Lazy Load if Possible
aGIFs to movies
No Base64 Encoded Images
Monitor Customer’s headers
Images Video
Optimize Image:
device screen (DPR?)
only download if displayed
Bitrate
Streaming is more efficient
Video can be expensive
120. Love Building with Video and Images?
Media Developer Expert
mde-comm@cloudinary.com
Become a
121. Addendum 3: Base64 Encoded Images
Fewer Requests *can* be better
Images in CSS place Images in the Critical Rendering path
Hardcoding images as text increases size by 20-30%