Hello Fellow Website Optimizers!
So I’ve been optimizing my website and think I have it pretty good. It gets a perfect rating on google pagespeed insights (lighthouse), gtmetrix.com and webpagetest.org. My only main weakness is TTFB as I’m currently self-hosting my site from home on a Synology NAS (protecting my origin IP with CloudFlare). I’ll fix my TTFB soon when I move the hosting.
However, my webpagetest.org results show a long ~1.2 second delay between first contentful paint and “fully loaded”.
I’m using the super popular “lazysizes” JS library to lazy load images on the site. The last 2 requests you see are lazy loaded images. However why such a long delay? It seems the browser main thread is mostly idle. Bandwidth is 0. Cpu utilization low-ish.
What does the long green bar on the bottom right of this waterfall mean?