Caching, Compression and Delivery
Caching and compression are among the most effective individual measures in performance optimization. Properly configured, they can reduce transferred data volume considerably and speed up repeat page views substantially. The following questions explain the different caching layers and compression methods we use in our performance projects. Learn more about our team and working methods on the About page.
In short and in plain language
On this page you will find questions and answers on the topic “Caching, Compression and Delivery”.
Each question has its own page with the answer. Below the question you see the start of the answer. Click on a question. Then you can read the whole answer.
At the bottom, a link takes you back to all questions.
- What is the difference between browser cache and server cache? Both caches speed up delivery, but they act at different points. The browser cache stores resources like images, CSS and JavaScript locally on the visitor's device. When the same…
- What is Brotli compression and why is it better than Gzip? Brotli is a compression algorithm developed by Google, tailored specifically to web content and shipping with a pre-trained dictionary of typical HTML and CSS patterns. Compared…
- How does a reverse proxy like Varnish work? A reverse proxy sits in front of the actual web server and keeps complete HTML pages in memory. When a visitor requests an already cached page, the proxy serves it directly from…
- What does Critical CSS mean and how is it implemented? Critical CSS is the minimum set of CSS rules needed to correctly render the immediately visible area of a page (above the fold). Normally the browser must first download and…
- How do I handle third-party scripts that slow down performance? Third-party scripts such as analytics tools, chat widgets, marketing pixels and social media embeds are among the most stubborn performance bottlenecks, because you do not control…
- How do I ensure performance remains stable after optimization? An optimized website can slow down again over time, which is normal and no sign of poor work. Regressions usually arise from new content, plugin updates or third-party scripts…