Improving performance with responsive (and responsible!) images [CSSDay.io]

CSSDay.io,
2015-12-05
https://github.com/nwtn/pres-respimg-perf-cssdayio

Transcript

1. 1 Improving performance with responsive (and responsible!) images
2. 1 Improving performance with responsive (and responsible!) images Don’t tell anybody, but this is an HTML talk.
6. 3 twitter @newtron github @nwtn slides nwtn.ca/d
7. 4 Web performance
8. “ 5 Many of us are fortunate to live in high bandwidth regions, but there are still large portions of the world that do not. By keeping your client side code small and lightweight, you can literally open your product up to new markets. —Chris Zacharias, Page Weight Matters (emphasis mine)
9. “ 6 Good performance is good design. —Brad Frost
10. 7 Why images?
11. 8 —Marc Andreessen, www-talk, February 1993
12. 9 Fonts 114 KB CSS 74 KB Video 187 KB HTML 52 KB Scripts 368 KB Other 4 KB Images 1,412 KB Total: 2,219 KB
14. “ 11 More human beings today have access to a cellphone than…a clean toilet. –Anand Giridharadas, New York Times April 10 2010
16. 13 — OpenSignal, Android Fragmentation Visualized (August 2014)
17. 14 —https://twitter.com/lukew/status/507880029737328640/photo/1
18. 15 A problem: We want images to look good e’rywhere
19. 16 img { max-width: 100%; }
23. 20 A solution: Serve one big image and let the browser scale it
26. 23 Bullet 1 Bullet 2 Bullet 3
27. 24 Bullet 1 Bullet 2 Bullet 3
29. 26 more pixels = more energy more pixels = more memory more pixels = more time
30. 27 A problem: We want images to look good e’rywhere
31. 28 A harder problem: We want images to look good e’rywhere, without hurting the user experience
32. 29 Responsive images
33. 30 A solution: Serve one big image and let the browser scale it
34. 31 A better solution: Serve an appropriate image to each user
38. 35 SVG WebP JPEG XR JPEG 2000
40. 37 Using CSS is a bad idea.
41. 38 Using JavaScript is a bad idea.
42. 39 http://whatwg.org/html#the-picture-element Responsive images specification
43. 40 Markup
44. 40 Resolution switching Markup
45. 41 <img src="wolf4800.jpg" alt="A rad wolf" />
46. 42 <img src="wolf4800.jpg" alt="A rad wolf" srcset="wolf300.jpg 0.5x, wolf600.jpg 1x, wolf1200.jpg 2x, wolf2400.jpg 3x, wolf4800.jpg 4x" />
47. 43 <img src="wolf4800.jpg" alt="A rad wolf" srcset="wolf300.jpg 0.5x, wolf600.jpg 1x, wolf1200.jpg 2x, wolf2400.jpg 3x, wolf4800.jpg 4x" />
48. 44 <img src="wolf4800.jpg" alt="A rad wolf" srcset="wolf300.jpg 0.5x, wolf600.jpg 1x, wolf1200.jpg 2x, wolf2400.jpg 3x, wolf4800.jpg 4x" />
49. 45 <img src="wolf4800.jpg" alt="A rad wolf" srcset="wolf300.jpg 0.5x, wolf600.jpg 1x, wolf1200.jpg 2x, wolf2400.jpg 3x, wolf4800.jpg 4x" />
50. 46 <img src="wolf600.jpg" alt="A rad wolf" srcset="wolf300.jpg 0.5x, wolf600.jpg 1x, wolf1200.jpg 2x, wolf2400.jpg 3x, wolf4800.jpg 4x" />
51. 47 <img src="wolf600.jpg" alt="A rad wolf" srcset="wolf300.jpg 0.5x, wolf600.jpg 1x, wolf1200.jpg 2x, wolf2400.jpg 3x, wolf4800.jpg 4x" />
52. 48 Viewport (and resolution!) switching Markup
53. 49 <img src="wolf4800.jpg" alt="A rad wolf" />
54. 50 <img src="wolf4800.jpg" alt="A rad wolf" sizes="100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
55. 51 <img src="wolf4800.jpg" alt="A rad wolf" sizes="100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
56. 52 <img src="wolf4800.jpg" alt="A rad wolf" sizes="100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
57. 53 <img src="wolf4800.jpg" alt="A rad wolf" sizes="100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
58. 54 <img src="wolf4800.jpg" alt="A rad wolf" sizes="100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
59. 55 <img src="wolf4800.jpg" alt="A rad wolf" sizes="600px" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
60. 56 <img src="wolf4800.jpg" alt="A rad wolf" sizes="calc(100vw - 10em)" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
61. 57 <img src="wolf4800.jpg" alt="A rad wolf" sizes="100%" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
63. 59 <img src="wolf4800.jpg" alt="A rad wolf" sizes="(min-width: 1000px) 33vw, (min-width: 600px) 50vw, 100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
64. 60 <img src="wolf4800.jpg" alt="A rad wolf" sizes="(min-width: 1000px) 33vw, (min-width: 600px) 50vw, 100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" />
65. 61 File type switching Markup
66. 62 <img src="wolf4800.jpg" alt="A rad wolf" />
67. 63 <picture> <source type="image/webp" srcset="wolf4800.webp" /> <img src="wolf4800.jpg" alt="A rad wolf" /> </picture>
68. 64 <picture> <source type="image/webp" srcset="wolf4800.webp" /> <img src="wolf4800.jpg" alt="A rad wolf" /> </picture>
69. 65 <picture> <source type="image/webp" srcset="wolf4800.webp" /> <img src="wolf4800.jpg" alt="A rad wolf" /> </picture>
70. 66 <picture> <source type="image/webp" srcset="wolf4800.webp" /> <img src="wolf4800.jpg" alt="A rad wolf" /> </picture>
71. 67 <picture> <source type="image/webp" srcset="wolf4800.webp" /> <source type="image/vnd.ms-photo" srcset="wolf4800.jxr" /> <img src="wolf4800.jpg" alt="A rad wolf" /> </picture>
72. 68 <picture> <source type="image/webp" srcset="wolf4800.webp" /> <source type="image/vnd.ms-photo" srcset="wolf4800.jxr" /> <img src="wolf4800.jpg" alt="A rad wolf" /> </picture>
73. 69 Art direction Markup
74. 70 —Adventure Time
77. 73 <img src="wolf4800.jpg" alt="A rad wolf" />
78. 74 <picture> <source media="(min-width: 1000px)" srcset="wolf-crop-bg.jpg" /> <source media="(min-width: 600px)" srcset="wolf-crop-sm.jpg" /> <img src="wolf.jpg" alt="A rad wolf" /> </picture>
79. 75 <picture> <source media="(min-width: 1000px)" srcset="wolf-crop-bg.jpg" /> <source media="(min-width: 600px)" srcset="wolf-crop-sm.jpg" /> <img src="wolf.jpg" alt="A rad wolf" /> </picture>
80. 76 <picture> <source media="(min-width: 1000px)" srcset="wolf-crop-bg.jpg" /> <source media="(min-width: 600px)" srcset="wolf-crop-sm.jpg" /> <img src="wolf.jpg" alt="A rad wolf" /> </picture>
81. 77 <picture> <source media="(min-width: 1000px)" srcset="wolf-crop-bg.jpg" /> <source media="(min-width: 600px)" srcset="wolf-crop-sm.jpg" /> <img src="wolf.jpg" alt="A rad wolf" /> </picture>
82. 78 <picture> <source media="(min-width: 1000px)" srcset="wolf-crop-bg.jpg" /> <source media="(min-width: 600px)" srcset="wolf-crop-sm.jpg" /> <img src="wolf.jpg" alt="A rad wolf" /> </picture>
83. 79 All the things! Markup a.k.a. the scary slide
84. 79 All the things! Markup a.k.a. the scary slide
85. 80 <picture> <source type="image/webp" media="(min-width: 1000px)" sizes="33vw" srcset="wolf-crop-big-300.jpg 300w, wolf-crop-big-600.jpg 600w, wolf-crop-big-1200.jpg 1200w, wolf-crop-big-2400.jpg 2400w, wolf-crop-big-4800.jpg 4800w" /> <source type="image/webp" media="(min-width: 600px)" sizes="50vw" srcset="wolf-crop-small-300.jpg 300w, wolf-crop-small-600.jpg 600w, wolf-crop-small-1200.jpg 1200w, wolf-crop-small-2400.jpg 2400w, wolf-crop-small-4800.jpg 4800w" /> <source type="image/webp" sizes="100vw" srcset="wolf-crop-med-300.jpg 300w, wolf-crop-med-600.jpg 600w, wolf-crop-med-1200.jpg 1200w, wolf-crop-med-2400.jpg 2400w, wolf-crop-med-4800.jpg 4800w" /> <source media="(min-width: 1000px)" sizes="33vw" srcset="wolf-crop-big-300.jpg 300w, wolf-crop-big-600.jpg 600w, wolf-crop-big-1200.jpg 1200w, wolf-crop-big-2400.jpg 2400w, wolf-crop-big-4800.jpg 4800w" /> <source media="(min-width: 600px)" sizes="50vw" srcset="wolf-crop-small-300.jpg 300w, wolf-crop-small-600.jpg 600w, wolf-crop-small-1200.jpg 1200w, wolf-crop-small-2400.jpg 2400w, wolf-crop-small-4800.jpg 4800w" /> <source sizes="100vw" srcset="wolf-crop-med-300.jpg 300w, wolf-crop-med-600.jpg 600w, wolf-crop-med-1200.jpg 1200w, wolf-crop-med-2400.jpg 2400w, wolf-crop-med-4800.jpg 4800w" /> <img src="wolf-crop-med-600.jpg" alt="A rad wolf" /> </picture>
86. <img src="wolf600.jpg" alt="A rad wolf" sizes="(min-width: 1000px) 33vw, (min-width: 600px) 50vw, 100vw" srcset="wolf300.jpg 300w, wolf600.jpg 600w, wolf1200.jpg 1200w, wolf2400.jpg 2400w, wolf4800.jpg 4800w" /> 81
87. 82 http://whatwg.org/html#the-picture-element Responsive images specification
88. 83 http://codepen.io/Tigt/blog/when-responsive-images-get-ugly When responsive images get ugly
89. 84 You can use this now!
90. 85 Firefox (Gecko) Chrome/Opera (Blink) Safari (WebKit) Edge srcset + sizes Works now! Firefox 38 Works now! Chrome 34 Opera 21 Works now! Safari 9 iOS 9 Works now! Edge 13 picture Works now! Firefox 38 Works now! Chrome 38 Opera 25 Almost there… Works now! Edge 13
91. 86 http://picturefill.responsiveimages.org/ Picturefill by Scott Jehl & others http://filamentgroup.com/lab/to-picturefill.html To Picturefill, or not to Picturefill
92. 87 Responsive images are a pain in the butt
94. 89 https://www.npmjs.com/package/grunt-respimg grunt-respimg
95. 90 https://github.com/nwtn/php-respimg/ php-respimg
96. https://www.npmjs.com/package/grunt-responsive-images-extender/ 91 grunt-responsive-images-extender
97. http://www.smashingmagazine.com/2015/06/efficient- image-resizing-with-imagemagick/ Efficient image resizing With ImageMagick 92
98. 93 Responsible images
99. 94 1. Responsive images
100. 95 1. Responsive images 2. Image optimization
101. 96 https://imageoptim.com/ ImageOptim https://github.com/toy/image_optim image_optim https://github.com/svg/svgo-gui SVGO-GUI https://github.com/svg/svgo SVGO
102. 97 SetOutputFilter DEFLATE AddOutputFilterByType DEFLATE "image/svg+xml"
103. 98 1. Responsive images 2. Image optimization 3. Deferred image loading (a.k.a. “lazy loading”)
106. 101 http://afarkas.github.io/lazysizes/ LazyLoad JS scripts and plugins, e.g.:
107. 102 1. Responsive images 2. Image optimization 3. Deferred image loading (a.k.a. “lazy loading”) 4. CDNs & Caching
108. 103 1. Responsive images 2. Image optimization 3. Deferred image loading (a.k.a. “lazy loading”) 4. CDNs & Caching 5. Appropriate contrast and colour
109. 104 7% 8% 10% 11% 29% 35% April May June July August September
110. 105 7% 8% 10% 11% 29% 35% April May June July August September
112. 107 http://colororacle.org/ Color Oracle
113. 108 September 7% August 8% July 10% June 11% May 29% April 35%
114. 109 1. Responsive images 2. Image optimization 3. Deferred image loading (a.k.a. “lazy loading”) 4. CDNs & Caching 5. Appropriate contrast and colour 6. Text-based alternatives
115. 110 [alt] [aria-describedby] [aria-labelledby] [longdesc] <a> <figcaption> SVG
116. 111 http://www.w3.org/TR/html-alt-techniques/ HTML5: Techniques for providing useful text alternatives http://www.w3.org/WAI/GL/wiki/Using_aria-describedby_to_provide_descriptions_of_images Using aria-describedby to provide descriptions of images http://w3c.github.io/test-results/html-longdesc/cr-report.html longdesc Implementation Report http://www.paciellogroup.com/blog/2013/12/using-aria-enhance-svg-accessibility/ Using ARIA to enhance SVG accessibility http://www.w3.org/WAI/GL/wiki/Using_aria-labelledby_to_provide_a_text_alternative_for_non- text_content Using aria-labelledby to provide a text alternative for non-text content
117. 112 1. Responsive images 2. Image optimization 3. Deferred image loading (a.k.a. “lazy loading”) 4. CDNs & Caching 5. Appropriate contrast and colour 6. Text-based alternatives 7. Fewer images!
118. “ 113 Good performance is good design. —Brad Frost
119. 114 https://www.shopify.com/careers We’re hiring!
120. 115 twitter @newtron github @nwtn slides nwtn.ca/d