HTTP 100 Continue vs 226 IM Used
HTTP 100 (Continue) is a 1xx Informational response, while 226 (IM Used) is a 2xx Success 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, 226 means that the server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations.
Description
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.
When You See It
When a client sends an Expect: 100-continue header, the server responds with 100 before the client sends the body.
How to Fix
This is an interim response — no fix needed. The client should continue sending the request body.
Description
The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations.
When You See It
When using delta encoding to reduce bandwidth.
How to Fix
Rarely encountered. The response uses Instance Manipulations (IM) as specified.
Key Differences
100 is a 1xx Informational response, while 226 is a 2xx Success 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 226: The server has fulfilled a GET request for the resource, and the response is a representation of the result of one or more instance-manipulations.
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 226 when when using delta encoding to reduce bandwidth.
When to Use Which
For 100 (Continue): This is an interim response — no fix needed. The client should continue sending the request body. For 226 (IM Used): Rarely encountered. The response uses Instance Manipulations (IM) as specified.