Comment by msm_
15 hours ago
>I personally don't remember any visual progressive image buildup in like decades, so it's not doing anything valuable at all.
Maybe you just don't notice? It can be pretty invisible sometimes. I sometimes notice that image soon after page load an image is slightly blurry, and then another pass "sharpens" it. Yeah it's not like in the "old times" when the first progressive level was almost unreadable, but there's still value in sending a lower resolution version of image in 30% of the total file-size, basically for free
I haven't been able to see it even setting Chrome developer tools to crazy slow network speeds. Maybe chrome developer tools simulation isn't enough to see it?
The observations you are reporting are from images you created yourself and you know are in fact progressive jpegs? (not "regressive", although that's funny). There are of course other techniques to start with a lower resolution image that do "work" (in the sense of actually displaying a lower resolution image first at least).