In-depth articles, tutorials, and guides on Performance — covering everything from fundamentals to advanced patterns.
Layout thrashing is one of the most common and most fixable causes of janky UIs. It happens when JavaScript forces the browser to repeatedly recalculate layout in a single frame — and it can turn a 60fps animation into a stuttering slideshow.
From the moment you type a URL to the moment pixels appear on screen, the browser executes a precise multi-stage pipeline. Understanding every stage — and what can interrupt each one — is the foundation for all frontend performance work.
Before a user sees anything on screen, the browser has to go through a precise sequence of steps. Understanding that sequence — the critical rendering path — is the foundation of every meaningful frontend performance optimization.