Cache-Control
Cache-Control is the header telling browsers and CDNs how long a response may be reused.
Why it matters
A one-year immutable header is only safe when every asset URL changes with its content, which is why version queries matter.
How it is measured
Fetch a static asset and read Cache-Control. Confirm max-age=31536000 and immutable.
Checks that involve cache-control
Related terms
Questions
What is cache-control?
Cache-Control is the header telling browsers and CDNs how long a response may be reused.
Why does cache-control matter?
A one-year immutable header is only safe when every asset URL changes with its content, which is why version queries matter.
How is cache-control measured?
Fetch a static asset and read Cache-Control. Confirm max-age=31536000 and immutable.