How Browsers Turn a URL Into a Webpage: The Rendering Pipeline Explained

A technical explainer on DEV Community breaks down the five key stages a browser goes through from the moment a user presses Enter to when pixels appear on screen. The process begins with network steps — DNS resolution, TCP handshake, and TLS handshake — before a single byte of HTML is received. The browser then parses HTML into a DOM tree and CSS into a CSSOM, both of which are combined into a Render Tree that excludes hidden elements. A Layout phase calculates exact pixel positions, followed by Paint and Compositing steps where the GPU renders final visuals. The article highlights performance implications, noting that animating CSS transform and opacity properties is faster because they bypass the costly Layout and Paint stages.