In this tutorial, we are going to explain what the HTTP 426 Error is and how to fix it. It belongs to the HTTP 4xx client errors family and indicates that the server refuses to perform the request using the current protocol. When this Error code is returned in the browser, that means the client needs to upgrade to a different protocol to communicate with the server. In the following paragraphs, we will explain in more detail what it is. We will cover the causes, the possible fixes, and their impact on the SEO of the website.
Table of Contents
What is the HTTP 426 Error?
The HTTP 426 error status code or Upgrade Required error indicates that the server requires the client to use a completely different protocol. Alternatively, it may need to upgrade the current protocol to a newer version to complete the request. When there is an HTTP 426 error, the server is not refusing the request altogether. Instead, it needs the client to update its communication. For example, if the server is configured to accept only HTTPS requests, a client’s HTTP request will be rejected. In this case, it would respond with an HTTP 426 error. Returning the HTTP 426 comes with the Upgrade header field in the response, where the required protocols are specified. The client needs to use these protocols for subsequent requests. Then, the client understands this response, upgrades its protocol, and resends the request using the new protocol.
The HTTP 426 error status code is rare and is usually used where the server requires a certain level of security. Additionally, it can be utilized in scenarios where the server requires newer and more advanced protocols, such as HTTP/2 and HTTP/3. It might also require an entirely different protocol, like WebSockets for real-time communication.
This was generally about what HTTP 426 is and how it works. Now, let’s proceed and explain the causes of this.
What are the causes for HTTP 426?
In this heading, we will explain the possible causes for the HTTP 426 error status code.
Unsupported Protocol Version: The server might disallow specific protocol versions. It may not support, for example, HTTP/1, but only HTTP/2 and HTTP/3 protocols.
Protocol Mismatch: The client may use an older incompatible version that the server no longer supports.
Server Misconfiguration: Sometimes the server might be incorrectly set up or require a protocol it doesn’t support. This is when the server is configured to accept the HTTP/1 protocol, but it does not support it due to its EOL.
Outdated Client Software is also one of the reasons for the HTTP 426 error. This means that the client may use an older web browser, and the protocol that requires the server is not supported within that web browser.
Security Policy: The server will enforce newer and more secure protocols such as HTTPS or WebSockets. When the client accesses the resources via an older insecure protocol, the server will return the HTTP 426 error.
How to fix it?
Fixing and avoiding the HTTP 426 error is straightforward. To resolve the issue, follow the next steps:
“Upgrade” Header: Checking the Upgrade header should be the first step after the HTTP 426 error. The “Upgrade” header contains the protocols it requires.
Upgrade Client Protocol: If you are using a modern browser to access the server resource, then the browser itself may automatically handle the protocol upgrade. Otherwise, if you are using a custom application to access the resource and get HTTP 426, then additional steps are required in the code. These steps may include switching from HTTP to HTTPS, or from HTTP/1 to HTTP/2, and HTTP/.3.
Check the Firewall: Check for any firewall settings that are improperly configured and prevent protocol upgrades.
Disable Proxy: If you have a proxy setting or are using a VPN, disable it temporarily to see if that will resolve the issue.
Check the Server Configuration to determine if there are any misconfigurations, such as unsupported protocols configured in the web server configuration.
Clear the web browser cache, cookies, and history, or try to access the website with a different web browser or incognito mode. Sometimes the browser may cache the old protocol and use it even after an upgrade.
How does HTTP 426 affect SEO?
The HTTP 426 error status code negatively impacts the SEO of the website. If a search engine crawler detects an HTTP 426 error automatically, the content of the website cannot be reached, and it cannot be indexed. Indexing issues will decrease the search rankings. Additionally, they will significantly reduce the organic traffic. The users will be frustrated if they continue to receive the HTTP 426 error. So, fixing the HTTP 426 is crucial for better website SEO.
Conclusion
These are the basic steps to perform to fix the HTTP 426 Error Status code. If the issue is server-related and you are not familiar with Linux, you can always contact our technical support. Simply sign up for our NVMe VPS server plans and submit a support ticket. We are available 24/7 and will be happy to assist you.
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