HTTP 204 No Content vs 426 Upgrade Required
Embed This Widget
Add the script tag and a data attribute to embed this widget.
Embed via iframe for maximum compatibility.
<iframe src="https://statuscodefyi.com/iframe/entity//" width="420" height="400" frameborder="0" style="border:0;border-radius:10px;max-width:100%" loading="lazy"></iframe>Paste this URL in WordPress, Medium, or any oEmbed-compatible platform.
https://statuscodefyi.com/entity//Add a dynamic SVG badge to your README or docs.
[](https://statuscodefyi.com/entity//)Use the native HTML custom element.
HTTP 204 (No Content) is a 2xx Success response, while 426 (Upgrade Required) is a 4xx Client Error response. 204 indicates that the server successfully processed the request but is not returning any content. Common for DELETE operations and form submissions that don't need a response body. 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 server successfully processed the request but is not returning any content. Common for DELETE operations and form submissions that don't need a response body.
When You See It
After DELETE requests, PUT updates where no body is needed, or CORS preflight responses.
How to Fix
No fix needed. The action was successful; there is simply no content to return.
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
204 is a 2xx Success response, while 426 is a 4xx Client Error response.
HTTP 204: The server successfully processed the request but is not returning any content. Common for DELETE operations and form submissions that don't need a response body.
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 204 when after DELETE requests, PUT updates where no body is needed, or CORS preflight responses.
You encounter 426 when when a server requires HTTPS or a newer protocol version.
When to Use Which
For 204 (No Content): No fix needed. The action was successful; there is simply no content to return. For 426 (Upgrade Required): Switch to the protocol specified in the Upgrade response header.