HTTP

HTTP 302 Found vs 426 Upgrade Required

HTTP 302 (Found) is a 3xx Redirection response, while 426 (Upgrade Required) is a 4xx Client Error response. 302 indicates that the resource temporarily resides at a different URL. The client should continue using the original URL for future requests. 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 temporarily resides at a different URL. The client should continue using the original URL for future requests.

When You See It

During A/B testing, temporary maintenance pages, or geo-based redirects.

How to Fix

Follow the Location header. Note: browsers may change POST to GET on redirect.

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

1.

302 is a 3xx Redirection response, while 426 is a 4xx Client Error response.

2.

HTTP 302: The resource temporarily resides at a different URL. The client should continue using the original URL for future requests.

3.

HTTP 426: The server refuses to perform the request using the current protocol but might after the client upgrades to a different protocol.

4.

You encounter 302 when during A/B testing, temporary maintenance pages, or geo-based redirects.

5.

You encounter 426 when when a server requires HTTPS or a newer protocol version.

When to Use Which

For 302 (Found): Follow the Location header. Note: browsers may change POST to GET on redirect. For 426 (Upgrade Required): Switch to the protocol specified in the Upgrade response header.

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