Posts tagged #performance

React 19.3 adds use(browser()), a first-class way to mark a component browser-only during SSR, replacing typeof window checks and useEffect mounted flags.

One slow resolver can hold a whole GraphQL response hostage. Here's how @defer and @stream split a query into an initial payload and patches, and what to check.

The back/forward cache restores pages from memory instantly, but an unload listener or no-store header can opt you out. Here's how to find and fix the blockers.

Nuxt 4.5 can flush your HTML shell before the page finishes rendering. Here's what experimental SSR streaming speeds up and the status code rule you need first.

Map and WeakMap now have getOrInsert and getOrInsertComputed, two methods that replace the check-then-set boilerplate every JavaScript codebase is full of.

Astro's live content collections fetch CMS and API data at request time with the same typed API as build-time collections, and route caching keeps them fast.

Compression Dictionary Transport (RFC 9842) lets the browser tell your server which file it has cached, so a redeployed bundle can arrive as a tiny delta.

JavaScript can finally turn bytes into base64 and hex without the String.fromCharCode and btoa dance. Here's how Uint8Array's new encoding methods work.

ES2026's import defer evaluates a module the first time you touch its namespace, not at startup, so heavy work leaves the cold path without going async.