THE BROWSER'S MAIN THREAD IS EXPENSIVE

Summary from the TLDR Dev newsletter

The browser's main thread runs JavaScript, handles input, and performs most of the rendering pipeline, leaving roughly 10ms of usable time per frame on a 60Hz display. Any task over 50ms risks visible jank. This guide shows how to split work around frame budgets, batch noisy events with debounce or throttle, prioritize and defer tasks, move animation to the compositor, use workers for atomic heavy work, and eliminate unnecessary computation.