Vary
Response headers
Names the headers that change the response; caches key on it.
| On the wire | Vary: … |
|---|---|
| Category | Response headers |
Headers the server attaches when it answers.
How to read this
- The first digit of a status code carries the meaning: 4 means the request, 5 means the server.
- 404 means "not there"; 403 means "there, but not for you". Swapping them makes debugging slower.
- Header names are case-insensitive — Content-Type and content-type are the same header.
- Caching and CORS problems usually come down to one header line, visible in the browser’s network tab.
Frequently asked questions
Q. What does HTTP Vary mean?
Names the headers that change the response; caches key on it.
Q. What does Vary look like on the wire?
It travels as Vary: …
Q. Where does Vary appear?
In response headers.
Q. What group does Vary belong to?
The response headers group; the rest of that group is listed further down.