What Is 404 Not Found?

In plain terms, a 404 is the web’s way of saying, “I looked, but that page isn’t here.” While it’s most commonly caused by a mistyped link or deleted page, in proxy-driven environments the situation can be more nuanced.

For example, if you’re running automated scraping through residential or datacenter proxies, you may hit 404s not because the content doesn’t exist, but because the target website serves different page structures depending on region, device, or request headers. In other cases, a proxy pool might route your request through an IP that doesn’t have access to that localized version of the page.

Think of it as knocking on a locked door—not because the building is gone, but because you approached it from the wrong side.

‍

How to Fix a 404 Error

‍

Check the URL

The most common reason is simply a bad link. Verify that the request your proxy is sending matches the correct path. Even small typos in query parameters can trigger a 404.

Rotate or Change Proxies

If the content exists but is geo-restricted, switching to a proxy in the right region can make the page accessible again. For example, a U.S. residential proxy may see a page that a European IP cannot.

Inspect Request Headers

Websites often tailor content based on headers like User-Agent or Accept-Language. If your proxy request strips or modifies these headers, the server may route you to a dead end.

Clear Cache and Cookies

When using proxies for scraping, cached sessions can conflict with new requests. Clearing them ensures you’re not asking for a stale resource that no longer exists.

Example in Code

Here’s a Python snippet using requests with proxies, handling a 404 gracefully:

import requests

proxies = {
    "http": "http://username:password@proxy_address:port",
    "https": "http://username:password@proxy_address:port"
}

url = "https://example.com/missing-page"

response = requests.get(url, proxies=proxies)

if response.status_code == 404:
    print("Page not found. Try a different URL or proxy.")

Web Scraping at Scale

When scraping thousands of pages through proxies, a spike in 404s can reveal issues in your crawler logic, like broken pagination or incorrect URL templates.

Regional Content Testing

Proxy providers often help businesses test how their website behaves in different countries. A 404 may indicate that a localized page isn’t configured properly for certain regions.

Map Error Patterns

If you see 404s concentrated in one region or proxy subnet, it could be a geo-restriction rather than a missing page. Mapping these patterns helps refine your proxy rotation strategy.

Implement Smart Retries

Instead of hammering the same dead URL, design your crawler to retry with a different proxy or adjust request headers before marking the resource as missing.

Monitor Logs with Proxy Context

Track 404 responses in your analytics, but always include proxy metadata—IP, ASN, region—so you can distinguish between real dead links and proxy-related routing issues.

A 404 Not Found error signals that the server couldn’t locate the requested page. In the proxy industry, it’s not always a simple case of a missing page—it can also mean your proxy routing, headers, or region doesn’t align with the server’s content delivery.

‍