405 Error: Method Not Allowed — Meaning, Causes & Full Fix Guide (2026)

HTTP 405 — Method Not Allowed

HTTP 405 is one of the most actionable error codes a server can return. Unlike the vague 500 or the frustrating 403, a 405 comes with a built-in diagnostic: the server is required by the HTTP specification to tell you exactly which methods it does accept on that resource. That means when you see a 405, the information you need to fix it is almost always in the same response.

This guide explains the precise meaning of 405, walks through every HTTP method so you understand the method landscape, covers the seven most common causes, and provides a complete fix checklist organised by audience — end users, developers, server administrators, and web scrapers.

What HTTP 405 Means — Precisely

The HTTP 405 status code means: "Method Not Allowed." As defined in MDN Web Docs: "The server knows the request method, but the target resource doesn't support this method."

Three things are simultaneously true when you receive a 405:

• The URL is valid. The resource exists — if it didn't, you would get 404.
• Your request was syntactically correct. If it were malformed, you would get 400.
• Authentication is not the issue. An auth failure would return 401 or 403.

The problem is specifically and only the HTTP method. The server understands every other part of your request and rejects exclusively the method verb. The practical implication: the fix does not involve URLs, authentication tokens, or request bodies — it involves changing which HTTP method you use, or configuring the server to accept the method you need.

Per RFC 9110 Section 15.5.6, the server must generate an Allow header in every 405 response listing the methods that resource currently supports. This is not optional — it is a protocol requirement. Always check the Allow header before doing anything else.

HTTP/1.1 405 Method Not Allowed
Allow: GET, POST, HEAD
Content-Type: application/json
Content-Length: 78

{"error": "Method Not Allowed", "allowed_methods": ["GET", "POST", "HEAD"]}

HTTP Methods: The Complete Reference

Understanding why 405 occurs requires knowing what each HTTP method is designed for. Mismatching a method to an endpoint's purpose is the single most common cause of 405 errors.

405 vs. Similar 4xx Error Codes

Status code definitions per MDN Web Docs HTTP 405; RFC 9110 comparison from Axentix HTTP 405 guide.

7 Root Causes of HTTP 405

3 Real-World Scenarios

How to Fix a 405 Error: Complete Checklist

Step 0: Read the Allow Header First

Before anything else, inspect the 405 response. The Allow header tells you exactly which methods the server accepts on that resource. With cURL:

curl -i -X GET https://api.example.com/endpoint

# Or send an OPTIONS request to discover allowed methods without
# triggering a full request:
curl -i -X OPTIONS https://api.example.com/endpoint

If the method you need is listed in Allow, the problem is not the method itself — it is a WAF, an authentication requirement, or an anti-bot block. If your method is absent from Allow, you need to either use a different method or configure the server to permit yours.

For End Users

For Developers

// Wrong — only GET registered:
app.get('/api/data', handler);

// Fix — add POST handler:
app.post('/api/data', handler);

// Or use router.all() to accept all methods (test environments only):
app.all('/api/data', handler);
  

For Server Administrators

# Overly restrictive — blocks POST, PUT, DELETE:
location /api/ {
    limit_except GET HEAD {
        deny all;
    }
}

# Fix — allow required methods:
location /api/ {
    limit_except GET HEAD POST PUT DELETE OPTIONS {
        deny all;
    }
}
  

# Remove or update restrictive LimitExcept blocks:
<LimitExcept GET HEAD POST>
    Require all denied
</LimitExcept>

# Ensure required methods (PUT, DELETE) are not in the deny list
  

405 in Web Scraping: The Anti-Bot Angle

For developers running web scraping pipelines, 405 errors fall into two categories with different root causes and fixes:

• Genuine method errors — your scraper is using the wrong HTTP method. Check the Allow header, verify the correct method against the target's API documentation, and update your code.
• Anti-bot method rejection — the server returns 405 even for valid methods when it detects automated traffic patterns. The Allow header lists your method as valid, but the 405 still occurs.

Identifying the second type: open the same URL in a real browser while using DevTools to inspect the request. If the browser gets a 200 using the same method your scraper sent, the rejection is based on the request's bot signals — not the method itself.

Fixing anti-bot 405 responses requires addressing the signals that triggered detection: browser-like request headers (User-Agent, Accept, Accept-Language, Accept-Encoding), realistic TLS fingerprints, and clean residential IP addresses that carry user-level trust scores. Nstproxy's residential proxy network provides IPs that pass the IP-layer checks, while scraping frameworks like Playwright or Puppeteer handle the browser-level fingerprint layer. See Nstproxy's high-anonymity proxy guide for request configuration details.

If you consistently receive 405 from protected targets despite correct methods, the proxy-based scraping guide covers the full stack approach for bypassing method-based anti-bot responses.

Conclusion

HTTP 405 is precise and actionable. It tells you the resource exists, your request syntax is valid, and authentication is not the issue — the only problem is the HTTP method. The Allow header in the 405 response tells you exactly what to use instead. Read it before doing anything else.

For developers, the fix is almost always in client code (wrong method) or route definitions (missing method handler). For server administrators, NGINX limit_except directives and Apache LimitExcept blocks are the most common misconfiguration sources. For web scrapers, the distinction between a genuine method error and an anti-bot 405 determines the entire fix strategy — one requires changing your request, the other requires changing your proxy and headers.

Frequently Asked Questions