Move over AppCache, there's a new API for building interactive, feature-rich applications: Service Workers.
When you think of web caching, you might picture a content delivery network (CDN), browser cache, or reverse proxy. These types of caches help deliver web pages and resources to visitors faster. But while these work great for static content, content that changes on each visit can be difficult or even impossible to cache, meaning your origin server has to do more work and respond to more requests.
The release of HTTP/2 in 2015 was a big win for the modern Web. While HTTP/1.1 worked well enough, it was built in an age before full two-way encryption, 1.9 MB web pages, and sub-3 second delivery times. We needed a modern protocol for a modern web, and HTTP/2 promised to deliver.
Brotli is an open source, lossless compression algorithm developed by Google. Originally designed to decrease the size of web fonts, Brotli now works as a general-purpose format for compressed data. Brotli acts as an alternative to gzip and Deflate, generating files that are smaller and decompress just as quickly.
JavaScript has a huge impact on web page performance, but much of this impact comes long before the script even runs. When a browser normally encounters a JavaScript block, it stops rendering the page in order to download and run the script. Where 38% of visitors will leave a website after waiting just 5 seconds for it to load, waiting on JavaScript simply isn't a viable option.