X-Cache
Indicates whether the request was a HIT or a MISS.
Fastly writes this header into responses. It is proprietary to Fastly.
Fastly appends this non-standard header to all responses by default, using a simplified derivative of the value of the fastly_info.state
variable. If the value of fastly_info.state
is HIT
or any value that starts with HIT-
then X-Cache
will be set to HIT
, otherwise MISS
.
Requests resulting in a PASS will be reported as MISS
, while requests resulting in edge-generated synthetic content will be reported as HIT
. Additionally all hits resulting from serving stale or background revalidations will also report as HIT
.
This header may contain reports from multiple servers, if shielding or Next-gen WAF at Edge is enabled, or if you use custom VCL code that invokes the restart
statement.
Other than in the case of a restart
, any entries in this header except "MISS" indicate that the request was satisfied from cache and not forwarded to origin (or Next-gen WAF at Edge)
You can remove this header, or make it subject to Fastly-Debug
, by using VCL in the vcl_deliver
subroutine (after the #FASTLY deliver
placeholder in custom VCL, or in a 'deliver' VCL snippet):
if (!req.http.Fastly-Debug) { unset resp.http.X-Cache;}