I built a test lab to measure SSG vs SSR vs ISR on real WordPress, here's what I found
Most "SSG vs SSR vs ISR" content out there is written from documentation. Someone reads the framework, restates it, and you're left inferring the actual difference in performance and behavior. So I built a lab where you can just run the commands and see it yourself, no table to trust blindly. astro-wp-seo-lab builds the same WordPress content four different ways with Astro 7.1.1, then serves all four side by side so you can compare them directly. git clone https://github.com/nimajafari/astro-wp-seo-lab npm install npm run compare That builds each arm into its own directory and serves them all at once. arm url what it is ssg-full http://localhost:4301 everything prerendered at build time ssr http://localhost:4302 rendered per request, no caching ssr-cdn http://localhost:4303 per request plus CDN cache headers route-cache http://localhost:4304 per request plus Astro 7 route caching islands http://localhost:4305 static shell with deferred fragments Every page has a black bar at the top showing which arm rendered it and when. That timestamp is the instrument for most of what follows. First build takes a few minutes since each arm fetches from WordPress, later builds are faster because the Content Layer loader caches between them. It ships pointed at a live WordPress install (oxyplug.com), but it works against any public WordPress site with the REST API exposed. npm run probe -- https://your-site.com --save mysite SOURCE = mysite npm run compare probe checks what your own install actually exposes, REST API reachability, Yoast presence, permalink structure, then saves it under a name. Use the URLs npm run compare prints for your own site instead of the ones below, since those are generated from your own content. Build time vs request time This is the distinction most of the SSG vs SSR debate hinges on, and it takes about 30 seconds to see for yourself. Open these two side by side and reload each a few times. http://localhost:4301/optimization/crl-ocsp-certificate-revocati