The 405 Method Not Allowed Error: What It Is and How to Fix It

You click a button, submit a form, or try to access an API endpoint, and instead of the expected result, your browser or application presents a stark and confusing message: "405 Method Not All Allowed." Unlike the more common 404 (Not Found) or 500 (Internal Server Error), the 405 is a very specific and often misunderstood HTTP status code.

This article will demystify the 405 error. We'll explain what it means, why it happens from both a user's and a developer's perspective, and provide a clear guide on how to fix it.

What Does "405 Method Not Allowed" Mean?

In simple terms, a 405 error means the server knows about the URL you're trying to access, but it doesn't allow the specific action (HTTP method) you're using to access it.

Think of it like a door:

The URL is the address of the door.
The HTTP method is the action you're trying to perform on the door.
A 404 error means the door doesn't exist.
A 405 error means the door exists, but you're trying to perform an action it wasn't designed for (e.g., trying to "PUSH" a door that clearly says "PULL").

Understanding HTTP Methods

To fully grasp the 405 error, you need a basic understanding of HTTP methods (or verbs). These are the core actions of the web:

GET: Retrieves data from the server. This is what your browser uses when you enter a URL or click a link. (e.g., viewing a blog post).
POST: Submits data to the server to create a new resource. (e.g., submitting a contact form or adding an item to a cart).
PUT: Submits data to update an existing resource entirely.
PATCH: Submits data to apply a partial update to an existing resource.
DELETE: Requests the deletion of a specified resource.

A 405 error occurs when there's a mismatch between the action (method) and the resource (URL).

Common Scenarios: Why You Might See a 405 Error

1. As an End-User (The Visitor)

You'll most often encounter this error due to a bug on the website you're visiting.

Misconfigured Forms: A web form (e.g., a login or search form) might be programmed to use the POST method when the server-side code for that URL only accepts GET requests, or vice-versa.
Faulty JavaScript/AJAX: Modern web apps use JavaScript to communicate with APIs. If the front-end code sends a PUT request to an endpoint that only allows GET and POST, it will trigger a 405.
Caching Issues: Sometimes, an old, cached version of a page might be trying to submit data to an endpoint that has since been changed or removed on the server.

What to do as a user:

Refresh the page. It's a classic for a reason—it can clear temporary glitches.
Clear your browser cache and cookies. This ensures you're loading the latest version of the site and its code.
Check if the website is down elsewhere. Use a tool like DownDetector to see if others are reporting issues.
Contact the website owner. If the problem persists, it's almost certainly a bug on their end. Report the URL you were trying to access and the action you were performing.

2. As a Developer or API Consumer

This is where the 405 error is most frequent and meaningful.

Incorrect API Endpoint Usage: This is the most common cause. You might be sending a POST request to an endpoint designed only for GET (e.g., trying to create a user at /api/users/123 instead of /api/users). Or, you might try to DELETE a resource that is not deletable via the API.
Web Server Configuration (Apache/nginx): Security configurations or rewrite rules can sometimes block certain methods (like PUT or DELETE) for entire directories, overriding your application code.
Framework Routing Issues: In frameworks like Laravel, Django, Express.js, or Spring, you define which HTTP methods a specific route (URL) can handle. If your route is only defined for POST and a GET request comes in, the framework will automatically return a 405.

How to Fix a 405 Method Not Allowed Error

If you're a developer facing this issue, here is a step-by-step debugging guide:

Double-Check the API Documentation:
This is always the first step. Ensure you are using the correct HTTP method (GET, POST, etc.) for the specific endpoint you are calling. A simple typo (PoST instead of POST) can be the culprit.
Inspect the Network Request:
Open your browser's Developer Tools (F12) and go to the "Network" tab. Reproduce the error and click on the failed request. Here you can confirm:
- The HTTP Method used (highlighted in red if there's an error).
- The Request URL that was called.
- The Status Code (405).
Verify Your Server-Side Code:
Check the routing in your application. For example:
- Express.js: Is your route defined as app.post('/submit', handler) but you're sending a GET?
- Laravel: In your routes/web.php or routes/api.php, does your route use Route::post() when it should accept multiple methods like Route::match(['get', 'post'], ...)?
Check for Server Configuration Files:
Look for configuration files like .htaccess (Apache) or nginx.conf (Nginx) that might be restricting methods. You might see directives like:

apache
```
# Apache .htaccess - Limit methods to only GET and POST
<LimitExcept GET POST>
    Deny from all
</LimitExcept>
```
Look at the Allow Header:
A proper 405 response must include an Allow header that lists the methods that are permitted for the requested URL. This is the server telling you exactly what you can do.
- In your browser's Dev Tools network tab, look at the "Response Headers" for the 405 request.
- You should see something like: Allow: GET, HEAD, POST
- This tells you immediately that your PUT or DELETE request was incorrect and what you should use instead.

Conclusion

The 405 Method Not Allowed error is a clear and specific message from the server about a protocol violation. For users, it's typically a sign of a website bug. For developers, it's a crucial debugging tool that points directly to a mismatch between the client's request and the server's defined API—often resolved by checking documentation, headers, and route configurations. By understanding the HTTP methods at play, you can quickly diagnose and resolve this precise HTTP status code.