HTTP 308 Permanent Redirect vs 426 Upgrade Required
HTTP 308 (Permanent Redirect) is a 3xx Redirection response, while 426 (Upgrade Required) is a 4xx Client Error response. 308 indicates that the resource has been permanently moved. Like 301, but guarantees the HTTP method will NOT be changed. In contrast, 426 means that the server refuses to perform the request using the current protocol but might after the client upgrades to a different protocol.
Description
The resource has been permanently moved. Like 301, but guarantees the HTTP method will NOT be changed.
When You See It
For permanent URL changes where POST requests must remain POST.
How to Fix
Update all references to the new URL. The HTTP method is preserved.
Description
The server refuses to perform the request using the current protocol but might after the client upgrades to a different protocol.
When You See It
When a server requires HTTPS or a newer protocol version.
How to Fix
Switch to the protocol specified in the Upgrade response header.
Key Differences
308 is a 3xx Redirection response, while 426 is a 4xx Client Error response.
HTTP 308: The resource has been permanently moved. Like 301, but guarantees the HTTP method will NOT be changed.
HTTP 426: The server refuses to perform the request using the current protocol but might after the client upgrades to a different protocol.
You encounter 308 when for permanent URL changes where POST requests must remain POST.
You encounter 426 when when a server requires HTTPS or a newer protocol version.
When to Use Which
For 308 (Permanent Redirect): Update all references to the new URL. The HTTP method is preserved. For 426 (Upgrade Required): Switch to the protocol specified in the Upgrade response header.