HTTP 100 Continue vs 303 See Other
HTTP 100 (Continue) is a 1xx Informational response, while 303 (See Other) is a 3xx Redirection response. 100 indicates that the server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected. 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
The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
Quando você o vê
When a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
Como corrigir
This is an interim response — no fix needed. The client should continue sending the request body.
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
100 is a 1xx Informational response, while 303 is a 3xx Redirection response.
HTTP 100: The server has received the request headers and the client should proceed to send the request body. This lets the client know it can continue with the request or abort if the headers were rejected.
HTTP 303: The server is redirecting to a different resource using GET, typically after a POST operation (Post/Redirect/Get pattern).
You encounter 100 when when a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
You encounter 303 when after form submissions to prevent resubmission on browser refresh.
Quando usar qual
For 100 (Continue): This is an interim response — no fix needed. The client should continue sending the request body. For 303 (See Other): Follow the Location header with a GET request. This is intentional — part of the PRG pattern.