ETag
An HTTP response header that provides a unique identifier for a resource version, used for cache validation and conditional requests. It is divided into strong and weak validators.
Timeline (last 90 days)
An ETag is a unique identifier generated by the server for a resource, and can be a strong or weak validator; Last-Modified is the timestamp of the resource's last modification.
A weak ETag cannot be used for validation of byte range requests, because it only guarantees semantic equivalence rather than byte-level consistency.
In CDN scenarios, the ETags returned by different nodes may be inconsistent.
All Facts (3)
An ETag is a unique identifier generated by the server for a resource, and can be a strong or weak validator; Last-Modified is the timestamp of the resource's last modification.
50%UnverifiedA weak ETag cannot be used for validation of byte range requests, because it only guarantees semantic equivalence rather than byte-level consistency.
50%UnverifiedIn CDN scenarios, the ETags returned by different nodes may be inconsistent.
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