HTTP 400 Bad Request vs 407 Proxy Authentication Required
Both HTTP 400 (Bad Request) and 407 (Proxy Authentication Required) belong to the 4xx Client Error category. 400 indicates that the server cannot process the request due to malformed syntax, invalid request message framing, or deceptive request routing. Meanwhile, 407 means that the client must first authenticate itself with the proxy.
Description
The server cannot process the request due to malformed syntax, invalid request message framing, or deceptive request routing.
When You See It
When sending malformed JSON, missing required fields, or invalid query parameters.
How to Fix
Check the request body format, validate all required fields, and ensure proper encoding.
Description
The client must first authenticate itself with the proxy.
When You See It
When accessing the internet through a corporate proxy that requires authentication.
How to Fix
Configure proxy credentials in your HTTP client or browser settings.
Key Differences
HTTP 400: The server cannot process the request due to malformed syntax, invalid request message framing, or deceptive request routing.
HTTP 407: The client must first authenticate itself with the proxy.
You encounter 400 when when sending malformed JSON, missing required fields, or invalid query parameters.
You encounter 407 when when accessing the internet through a corporate proxy that requires authentication.
When to Use Which
For 400 (Bad Request): Check the request body format, validate all required fields, and ensure proper encoding. For 407 (Proxy Authentication Required): Configure proxy credentials in your HTTP client or browser settings.