What impact does server-side compression (such as gzip or Brotli) have on page transfer performance and search engine crawling?

When website servers enable compression technologies such as gzip or Brotli, they can usually significantly optimize page transmission performance and have a positive impact on search engine crawling. **Impact on transmission performance**: Compression reduces the size of text resources such as HTML, CSS, and JavaScript through algorithms (typically achieving a compression rate of 50%-80%), directly reducing data transmission volume, lowering bandwidth consumption, and shortening page loading time. This is particularly beneficial for improving user experience in mobile networks or low-bandwidth environments. **Impact on search engine crawling**: Smaller file sizes allow search engine crawlers to download page content faster, save crawling quotas, help crawlers crawl more pages efficiently, and indirectly increase the probability of content being indexed. However, it should be noted that the server needs to correctly configure compression rules (such as specifying compressed MIME types) and avoid compressing already compressed resources (such as images and videos), which may lead to adverse effects. It is recommended that websites prioritize enabling Brotli for text resources (which usually has a higher compression rate than gzip), and test the compression effect through tools (such as PageSpeed Insights) to ensure that the server response headers correctly return compression identifiers (such as Content-Encoding: br), so as to balance performance optimization and search engine crawling efficiency.