HTTP 101 Switching Protocols vs 402 Payment Required
HTTP 101 (Switching Protocols) is a 1xx Informational response, while 402 (Payment Required) is a 4xx Client Error response. 101 indicates that the server understands the Upgrade header field request and indicates which protocol it is switching to. In contrast, 402 means that reserved for future use. Originally intended for digital payment systems, some APIs use it to indicate a billing or subscription issue.
Description
The server understands the Upgrade header field request and indicates which protocol it is switching to.
When You See It
When upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
How to Fix
This is normal behavior during protocol upgrades. Ensure your client supports the target protocol.
Description
Reserved for future use. Originally intended for digital payment systems, some APIs use it to indicate a billing or subscription issue.
When You See It
On some APIs when a subscription has expired or payment is needed.
How to Fix
Check your billing status, update payment method, or upgrade your subscription.
Key Differences
101 is a 1xx Informational response, while 402 is a 4xx Client Error response.
HTTP 101: The server understands the Upgrade header field request and indicates which protocol it is switching to.
HTTP 402: Reserved for future use. Originally intended for digital payment systems, some APIs use it to indicate a billing or subscription issue.
You encounter 101 when when upgrading from HTTP/1.1 to WebSocket, or to HTTP/2.
You encounter 402 when on some APIs when a subscription has expired or payment is needed.
When to Use Which
For 101 (Switching Protocols): This is normal behavior during protocol upgrades. Ensure your client supports the target protocol. For 402 (Payment Required): Check your billing status, update payment method, or upgrade your subscription.