Read this exclusive article to learn how to:
- Harness the power of Vary (while avoiding pitfalls)
- Preserve your cache hit ratio for better end-user experiences
- A/B test at the edge, closer to users
- Normalize bad Vary headers (and why they’re bad)
Vary is one of the most powerful HTTP response headers, enabling efficient objection compression, device detection, A/B testing at the edge, and more. Using it incorrectly, however, can have disastrous effects. Seasoned performance veteran and Fastly engineer Rogier “Doc” Mulhuijzen walks you through best practices for using Vary, including use cases and code snippets for putting Vary to work.
Check your inbox to read our article on best practices for using the Vary header.