Browser Diet

Most performance guides start at the browser: minify your JavaScript, compress your images, cut your render-blocking CSS. All of that matters — but by the time the browser gets to render anything, a whole chain of events has already happened. And if that chain is slow, no amount of front-end optimization will save your Time … Read more

Typography is usually the first place a redesign gets ambitious and the last place anyone checks the performance bill. Four font families, three weights each, loaded from two origins — and suddenly your text is invisible for two seconds on a phone. Here’s the diet version. 1. font-display decides what users see The single highest-leverage … Read more

Images are still the heaviest thing most pages ship, and the format menu has never been longer. Here’s the short version of a long argument. AVIF: best compression, some caveats AVIF routinely lands 30–50% smaller than JPEG at comparable visual quality, handles HDR and wide gamut, and every current browser supports it. The caveats: encoding … Read more

For years, Core Web Vitals measured responsiveness with First Input Delay. FID had a comfortable problem: almost everybody passed it. A page could freeze for half a second every time you tapped a menu and still score green, because FID only measured the first interaction — and only its input delay, not the work that … Read more