Server-sent events allow web servers to push real-time event notifications to the browser on a long-lived HTTP response. It's a beautiful part of the web platform that’s severely underused…

You can use the Vary response header in creative ways, including A/B testing and internationalization. At the same time, many people still use Vary badly or misunderstand what it does; in…

Surrogate keys give Fastly customers a unique way to efficiently purge content from cache — batch API for surrogate key purge allows you to purge content even more efficiently by purging…

Since we made HTTP/2 generally available in November 2016, h2 traffic has been steadily growing as more customers migrate to the new version of the protocol; since the beginning of 2017, h…

CDN and caching can get confused for one another. Learn the differences between CDN and caching to help decide what you should use for optimal web performance.

Cache hit ratio is a common metric that evaluates a CDN's performance. Learn more about how to improve your cache hit ratio.

Our CDN can cache more content than traditional solutions (static as well as rapidly changing, “event-driven” content), offloading traffic that would otherwise go to origin, allowing our…

At Altitude 2016, Software Engineer Alex Russell discussed the latest projects the “performance obsessed” Google Chrome team had underway. In this recap, we’ll take a look at how you can…

The Fastly API is an integral part of our CDN — using our APIs, customers are able to instantly reflect configuration changes, purge content, and perform anything that is available on the…

A/B testing is valuable, aggravating, and everyone has an opinion on the best way to do it. At Fastly, we provide a set of tools to help enable experiments you can integrate into your own…

HashiCorp’s Director of Technical Advocacy discusses Terraform, their tool for building, changing, and versioning infrastructure safely and efficiently, and how they use it to codify Fastly…