Brotli is a lossless data compression algorithm developed by Google that typically achieves 15–25% smaller file sizes than gzip for HTML, CSS, and JavaScript assets. Serving smaller text files over the network reduces download time, which improves page load speed and contributes to better [Core Web Vitals](/glossary/core-web-vitals) scores. Brotli is supported by all modern browsers and most web servers and CDNs, often enabled with a single configuration option. Gzip remains a useful fallback for older clients that do not send `Accept-Encoding: br` in their request headers.