June 8th, 2020 × #performance#images#video#service workers
Hasty Treat - Slow Connections Part 2
Wes Bos and Scott Tolinski continue their series on web performance, focusing on tips for making websites work well on slow Internet connections.
In this Hasty Treat, Scott and Wes are back with part 2 on how to develop for slow internet connections.
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Show Notes
03:27 - Images
- Resize client-side when uploading
- Lazy load or progressive JPG
- Width + height so the content doesn't shift with placeholders
- Compress your images - lossless and lossy
- Use SVG where possible
08:33 - Scripts + CSS assets
- Hasty Treat - 5 Things That Make Your Site Slow
- Hasty Treat - 5 More Things That Make Your Site Slow
08:51 - Video
- Variable-rate video is key
09:13 - Connections that go in-n-out a lot
- Save form state on page refresh
- Show UI when user goes offline
window.addEventListener('offline', updateOnlineStatus);
window.addEventListener('online', updateOnlineStatus);
- Retrying in _____
10:27 - Service workers!
- Serves up local cache initially
12:05 - Fonts
- Font-display CSS https://css-tricks.com/font-display-masses/
- Sometimes possible: tree shake your fonts - load only the characters you need
font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
14:04 - CSS tricks
- Text over background image — make sure you also set a color so the text will show while the image is loading
14:37 - Testing slow connections
- Dev tools
- Mimic a speed, or 3G
Links
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- Wes' Twitter
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- Scott's Twitter
- Make sure to include @SyntaxFM in your tweets