HTTP 103 Early Hints vs 303 See Other
HTTP 103 (Early Hints) is a 1xx Informational response, while 303 (See Other) is a 3xx Redirection response. 103 indicates that used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response. In contrast, 303 means that the server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
Descrição
Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
Quando você o vê
When a server wants the browser to start loading CSS/JS before the full response is ready.
Como corrigir
No fix needed. This optimization helps speed up page loading.
Descrição
The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
Quando você o vê
After form submissions to prevent resubmission on browser refresh.
Como corrigir
Follow the Location header with a GET request. This is intentional — part of the PRG pattern.
Diferenças principais
103 is a 1xx Informational response, while 303 is a 3xx Redirection response.
HTTP 103: Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.
HTTP 303: The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
You encounter 103 when when a server wants the browser to start loading CSS/JS before the full response is ready.
You encounter 303 when after form submissions to prevent resubmission on browser refresh.
Quando usar qual
For 103 (Early Hints): No fix needed. This optimization helps speed up page loading. For 303 (See Other): Follow the Location header with a GET request. This is intentional — part of the PRG pattern.