Improve site performance by inlining your CSS

Building a website or application often begins with a highly efficient index.html file, but as features are added, performance can degrade over time. Inlining CSS is a recommended strategy for improving site performance by embedding critical styles directly into the HTML, thereby reducing the number of render-blocking network requests that a browser must make before displaying a page. This method is contrasted with less efficient inlining practices that can lead to performance losses due to increased specificity and duplication of styles. The article emphasizes the importance of measuring current performance metrics before implementing changes and suggests using tools like Chrome's coverage feature, Penthouse, and Addy Osmani's Critical to manage CSS inlining effectively. By identifying and inlining only the critical CSS needed for the initial page load while deferring non-critical styles, developers can enhance the user experience by reducing load times, though it's crucial to balance the trade-off between a larger HTML file and fewer network requests.