HTTP

HTTP 103 Early Hints vs 411 Length Required

HTTP 103 (Early Hints) is a 1xx Informational response, while 411 (Length Required) is a 4xx Client Error 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, 411 means that the server refuses to accept the request without a Content-Length header.

Description

Used to return some response headers before the final HTTP message. Allows the browser to start preloading resources while the server prepares the response.

When You See It

When a server wants the browser to start loading CSS/JS before the full response is ready.

How to Fix

No fix needed. This optimization helps speed up page loading.

Description

The server refuses to accept the request without a Content-Length header.

When You See It

When sending a request body without specifying Content-Length.

How to Fix

Include a Content-Length header in your request.

Key Differences

1.

103 is a 1xx Informational response, while 411 is a 4xx Client Error response.

2.

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.

3.

HTTP 411: The server refuses to accept the request without a Content-Length header.

4.

You encounter 103 when when a server wants the browser to start loading CSS/JS before the full response is ready.

5.

You encounter 411 when when sending a request body without specifying Content-Length.

When to Use Which

For 103 (Early Hints): No fix needed. This optimization helps speed up page loading. For 411 (Length Required): Include a Content-Length header in your request.

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