As a #webperformance engineer I often have to look at “waterfall charts” to see when network requests occur to spot bottlenecks. I wondered what they might SOUND like, so made a little tool to listen to them.
https://calendar.perfplanet.com/2024/how-does-web-performance-sound/
https://screenspan.net/soundtrace
https://calendar.perfplanet.com/2024/how-does-web-performance-sound/
https://screenspan.net/soundtrace
Comments
I immediately heard that something was off with https://bsky.app when playing my latest reload's .har. The fonts files are massive. :-D
I noticed a few more issues with the fonts. 🙈
- there's no subsetting
- they are preloaded without crossorigin attribute, which causes double-downloading (see https://github.com/w3c/preload/issues/32)
- the Italic font is probably not used often enough to justify a preload
What I just realised:
On EVERY refresh the fonts are downloaded twice and not served from cache!
The alternating CO/non-CO requests seem to be messing with the files' caches, at least in all Chromium browsers I tested. In fact, this behaviour is the only reason I HEARD it.