Content-Length
The anticipated size of the request or response body, as a decimal number of octets, sent to the recipient.
Fastly reads this header from requests and responses and writes it into requests and responses. It is defined by an external standard.
PROTECTED: This header cannot be modified in VCL.
When a message does not have a Transfer-Encoding header field, a Content-Length header field can provide the anticipated size, as a decimal number of octets, for a potential payload body. For messages that do include a payload body, the Content-Length field-value provides the framing information necessary for determining where the body (and message) ends. For messages that do not include a payload body, the Content-Length indicates the size of the selected representation (Section 3 of RFC7231).
User contributed notes
BETADo you see an error in this page? Do have an interesting use case, example or edge case people should know about? Share your knowledge and help people who are reading this page! (Comments are moderated; for support, please contact support@fastly.com)