is used to indicate that particular server behaviors are required by the client.
Quick facts
Description
is used to indicate that particular server behaviors are required by the client.
Syntax
Expect: 100-continue
Related status codes
Frequently asked questions
is used to indicate that particular server behaviors are required by the client.
It is classified as a request header and can appear in requests or responses depending on context.
Sources & standards
Updated 2026-09-13
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