Understanding 405 Error: Causes, Fixes, and Prevention Strategies

HTTP status codes and error messages inform the client of what happened and whether the request experienced issues. While they are crucial for troubleshooting, you’ll need to know more about them to solve the causes and prevent them in the future.

The ‘405 Method Not Allowed’ error is no exception. It’s one of the many HTTP error codes you’ll encounter while web scraping or administering a web server. Fixes are often quick and easy, but other times, you might need to dig deeper into the root causes.

What Is the HTTP 405 Error and What Does It Mean?

A 405 error means that the client attempts to interact with the server using an HTTP method it does not permit for the requested resource. The server logs the request itself but cannot complete it because the HTTP request method isn’t listed under the Allow header.

It’s like trying to sell (POST) your groceries to the local supermarket when it only expects you to receive (GET) them. This might be possible under different circumstances (using the back door, for example), but you need a different resource or a different request method.

Analogies aside, the HTTP status code 405 error does cause real accessibility issues in many tasks and can appear under different forms. While they slightly differ depending on the web server, they all inform you about the same problem.

• 405 Method Not Allowed
• HTTP 405 Method Not Allowed
• HTTP Error 405 – Method Not Allowed
• 405 Not Allowed
• Error 405: Method Not Allowed
• 405 HTTP Method Not Allowed
• Method Not Allowed Error
• The requested method POST is not allowed for the URL
• Server 405 Error – HTTP Verb used to access this page is not allowed
• This page isn’t working – HTTP ERROR 405

The ‘405 Method Not Allowed’ error belongs to a class of 4xx HTTP errors indicating a client-side issue. These HTTP status errors are related to the user’s device or browser (the client) when interacting with a web server. So, troubleshooting should start by assuming that something went wrong with the request or how it was handled on the client’s side.

Yet, in some cases, 405 errors can still be triggered by the server itself to specific clients. This can happen unintentionally due to server configuration issues or even intentionally when the web server software seeks to restrict certain requests.

What Triggers the 405 Error?

We already know that a 405 error message occurs when there’s a mismatch between the request method the client uses and the HTTP method the server resource supports. To get into the specifics of what triggers it, we must look into the most common types of HTTP requests supported by web servers.

• GET is used to request data from a server, such as to load a webpage.
• POST sends data to the server, such as entering a username.
• PUT updates the existing data or creates a source at a known URL, such as changing your user name.
• DELETE can remove data from the web server.
• PATCH applies partial updates, such as changing your last name only.
• HEAD can retrieve only headers, but not files, for example, the metadata of a picture, but not the picture itself.

The client, such as a web scraper, can discover the accepted HTTP methods through the Allow header found through the OPTIONS request. On the server side, the available HTTP request methods are specified in the server config files.

HTTP method misuse and mismatches are some of the most common reasons for 405 errors. If your browser, web scraper, or other client is sending GET where only DELETE and PATCH are allowed by the server, you will get a ‘405 Method Not Allowed’ error.

Misconfigured routes in the server itself can create 405 errors as well. Server configuration limits in Apache, for example, may restrict specific HTTP request methods for certain URLs. If users are often using request methods that aren’t allowed, server-side logs will reflect that, and server administrators should take action.

Sometimes, 405 errors may start to appear from seemingly unrelated changes. For example, installing a new CMS plugin or changing file permission rules might unintentionally change what HTTP methods are allowed for certain URLs.

If your web scraper or other automation software receives 405 errors, but they aren’t apparent to other clients, it might mean you are blocked. The website might be misconfigured on purpose to confuse bots or simply display a 405 error code, although the error reason is different.

405 vs Other HTTP Errors: What’s the Difference?

The ‘405 Method Not Allowed’ error is often confused with other 4xx-type errors. The causes for their occurrence might be related, but the solution to the ‘Method Not Allowed’ error requires other means. It’s important to learn how to differentiate these HTTP status codes to make your troubleshooting easier.

405 vs 404 (Not Found)

The difference between 405 and 404 error codes lies in whether the requested resource exists. In the case of a 404 error, the requested resource doesn’t exist. However, when you get a 405 error code, the resource does exist, but you need to send a different request method.

405 vs 400 (Bad Request)

The 400 error code relates to the form of the request. They might be malformed or have bad syntax, which prevents the server from fully understanding them. Unlike the ‘405 Method Not Allowed’ error, the request itself is permitted, but it needs to be formulated differently by the client.

405 vs 403 (Forbidden)

While ‘405 Method Not Allowed’ informs about the HTTP method being not permitted, 403 errors show that the client is forbidden. The HTTP request might be well-formed and allowed for the resource, but the client does not have access, such as admin privileges, to access it.

405 vs 401 (Unauthorized)

The 401 error code informs about missing or invalid client authentication. Unlike the ‘405 Method Not Allowed’ error, it doesn’t have anything to do with the acceptance of the HTTP method. The HTTP method and the resource are understood, but the request is denied due to invalid authentication.

405 vs 415 (Unsupported Media Type)

The 415 error code means that the server rejected the client’s request because the media type in the Content-Type header is unsupported or unknown. For example, uploading a PDF when a JPG is supported. This is different from 405 errors, where the method is not allowed, while the media type might be appropriate.

How to Fix the ‘405 Method Not Allowed’ Error (For Developers & Admins)

Developers may encounter the 405 error when creating automation tools. In such cases, solving this error message usually requires changing the default HTTP request method. The exact solution depends on the tools and language of your project. We’ll suppose you’re using a Python script for implementing an API or a scraper.

You’ll need the requests library, which allows specifying the HTTP method used. You can specify one particular method, such as requests.get() for GET requests, but often it’s more effective to use the more general requests.request(method, url, …), where method can be replaced with the needed HTTP method.

import requests

#Defining the URL
url = "https://iproyal.com/"

#Defining the headers to use
headers = {
    "User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/125.0.0.0 Safari/537.36"
}

# Choose the HTTP method to test
method = "GET"  # You can change this to POST, PUT, DELETE, etc.

#Sending a request

response = requests.request(method, url, headers=headers)

# Print status code
print(response.status_code)
print(response.text)

Changing HTTP methods from GET to POST, for example, can solve the 405 error when you are trying to implement an automation script or set up an API with Python. If none of the methods work, it might mean that you are blocked. Using rotating proxies and testing your headers might be a solution.

Website administrators have many more options to deal with the 405 errors because they control and configure the server's behavior. At the same time, server administrators can unintentionally create 405 errors for visitors if the server configuration is incorrect. Here are some common troubleshooting steps.

• Revert server updates if the 405 error starts to appear after them. Make sure to create a backup before making changes.
• Review server-side logs (access.log, error.log), looking for requests with disallowed HTTP methods and problematic URLs.
• Inspect the server logs and configuration files for rules limiting HTTP methods. For Apache servers, for example, look into .htaccess file rules like or within the root directory.
• Try to replicate the 405 error in a local or staging environment and debug associated scripts or application code if necessary.
• Verify whether APIs are set up correctly and use route methods appropriate for your HTTP request rules. API testing tools, like Postman or Curl, are useful here to try out changes.
• Check firewalls or other security plugins that may block some HTTP methods by default.

How to Prevent 405 Errors on Your Website

Quick troubleshooting of error messages is essential in most cases, especially when dealing with proxy error codes , but if you administer a website, it's more important to prevent 405 errors. Implementing at least some of the good practices will save you from a lot of hassle when solving 405 or other 4xx issues later.

• Validate front-end forms and application code to ensure all requests use the correct HTTP routes.
• Test APIS and follow REST API method specifications to ensure each endpoint supports only appropriate HTTP methods. Always explicitly define each route.
• Monitor server-side errors and server logs to detect method mismatches, creating 405 errors early.
• Audit server configuration files, such as nginx.conf or .htaccess files, for routing rules.
• Perform updates in testing or staging environments before applying the changes to avoid 405 errors.
• Regularly back up your web server.

Conclusion

All larger websites and automation projects are bound to face 405 errors at some point. It's more important to be prepared to detect and resolve them quickly. Now that you have a thorough understanding of the ‘405 Method Not Allowed’ error, you can achieve just that.