How to fix ERR_PROXY_CONNECTION_FAILED error

ERR_PROXY_CONNECTION_FAILED is a common browser error that indicates the proxy connection did not work as expected. It usually signals a problem with the network configuration or the proxy service itself. The issue is usually temporary and can be resolved by adjusting a few settings. In this guide you will learn what the error means, its main causes, and the steps to fix it.

What “ERR_PROXY_CONNECTION_FAILED” Means

ERR_PROXY_CONNECTION_FAILED is a browser error that appears when a connection through the configured proxy server cannot be established. Instead of loading the requested page, the browser displays this message to indicate that proxy communication was unsuccessful. In simple terms, the proxy connection failed, so your request never reached the target website.

This error most often shows up in browsers such as Chrome when proxy settings are incorrect at the system level. It can also appear in other browsers, in operating system network settings, or in developer tools when testing requests through a proxy. Developers may notice it in Chrome DevTools or with command-line tools like curl when the proxy server fails to respond.

If instead you are facing a “Proxy Server Refused Connection” error, that means the proxy is reachable but rejects the request. In that case, refer to our guide on fixing Proxy Server Refused Connection errors for step-by-step solutions.

Common Causes of ERR_PROXY_CONNECTION_FAILED Errors

Wrong proxy IP, port, or protocol mismatch

One of the most frequent reasons for this error is an incorrect proxy address, port, or protocol. If the proxy server details are typed incorrectly, or if you configure SOCKS5 while the server only supports HTTP/HTTPS, the browser cannot complete the handshake. This leads to an immediate failure where the request never leaves your machine. Always verify that the proxy host or IP address, port number, and protocol type match the details provided by your proxy service.

Invalid or expired proxy credentials

If your proxy requires authentication, the browser must send the correct username and password. A simple typo, expired subscription, or an account that has run out of traffic can cause the connection to fail. In these cases, the proxy server rejects the request before it reaches the target site. Checking your login details or renewing your subscription often resolves this issue.

VPN, firewall, or antivirus interference

Security software or active VPN connections can override or block proxy traffic. A firewall rule may prevent traffic from leaving the configured port, or an antivirus tool may intercept requests for scanning. Similarly, running a VPN alongside a proxy can create conflicts where the system routes traffic incorrectly. If ERR_PROXY_CONNECTION_FAILED only appears on certain networks or disappears after disabling a VPN, interference from security tools is the likely cause.

Proxy server downtime or user limits

Sometimes the problem is not on your side. Proxy servers may be temporarily offline for maintenance, overloaded during peak times, or enforcing user limits on bandwidth or concurrent sessions. When this happens, even correct settings fail because the server is not accepting new connections. If the error only occurs intermittently or resolves when switching to another location or node, the proxy provider’s availability or limits may be the root cause.

Fix 1: Check and correct proxy settings (IP, port, protocol, credentials)

The first step is to confirm that your proxy settings are correct. A typo in the server address, port, or protocol can immediately block the connection.

Windows: Go to Settings → Network & Internet → Proxy and confirm the server address and port.
macOS: Open System Settings → Network → Proxies and review the configuration.
Android: Under your Wi-Fi connection, tap Advanced settings → Proxy and re-enter the details.

Make sure the protocol type (HTTP, HTTPS, or SOCKS5) matches what your provider supports. If your proxy requires authentication, carefully re-enter the username and password. For services that use IP whitelisting, verify that your current public IP is authorized.

Developer tip: Test basic connectivity with ping or telnet proxy_host port number.

Fix 2: Disable VPN or firewall temporarily

If your settings look correct but the error persists, a VPN client, firewall, or antivirus tool may be interfering with proxy traffic.

Temporarily disable your VPN and check if the error disappears.
On Windows or macOS, turn off the firewall for a short test and retry.
Pause antivirus network protection if enabled.

If disabling one of these tools resolves the error, add an exception rule to allow proxy traffic. Do not leave security features permanently disabled—this is only for troubleshooting.

Developer tip: If the proxy works on a mobile hotspot but not on a corporate or campus network, the local firewall may be blocking the proxy port.

Fix 3: Switch port or protocol if supported

Some networks restrict certain ports or protocols. If your proxy provider offers alternatives, try switching.

Change the port to 8080, 3128, or 1080 if available.
Switch between HTTP, HTTPS, or SOCKS5 depending on what your provider supports.

This is particularly useful in corporate or university networks where firewall rules silently block non-standard traffic.

Developer tip: Run a traceroute or use curl -x with different protocols to see which requests succeed.

Fix 4: Test proxy directly with Postman or curl

If the previous fixes do not solve the error, the next step is to verify whether the proxy itself is working. Running a quick test with curl or Postman won’t fix the issue directly, but it helps determine whether the problem is local or on the proxy server.

With Postman: Open Settings → Proxy, enter the host, port, and login details from your provider, and send a simple request (for example, https://httpbin.org/ip). If it fails, the proxy server may be offline or rejecting connections.

With curl (developer-friendly):

# HTTP/HTTPS proxy with authentication
curl -x http://user:pass@geo.ipcook.com:32345 https://httpbin.org/ip -I  

# SOCKS5 proxy
curl --socks5-hostname geo.ipcook.com:1080 https://ifconfig.me -I

In this example, the proxy list comes from IPcook, where you can easily copy all proxy details directly from the dashboard. Here, geo.ipcook.com is the proxy host, 32345 or 1080 are sample port numbers, and user:pass are your login credentials. The target URL such as https://httpbin.org/ip simply checks whether the proxy returns your IP address. Replace these values with the details from your IPcook account before running the command. For detailed setup steps on testing proxy connectivity from the command line using curl, see our Curl Proxy Guide.

An HTTP response with status code 200 means the proxy is working. A 407 Proxy Authentication Required response points to login issues, while timeout or connection errors suggest a blocked port or server downtime. For errors such as 403, 429, 502, or 503 after connecting through a proxy, see our guide on fixing received HTTP code from proxy after connect.

Conclusion

ERR_PROXY_CONNECTION_FAILED is a common proxy error that signals your browser could not connect through the configured server. In most cases, it comes down to incorrect settings, blocked traffic from VPNs or firewalls, or temporary proxy server issues. By carefully checking your configuration, ruling out conflicts, and testing the connection directly, you can usually resolve the problem in just a few steps.

If the error continues to appear even after troubleshooting, it often comes down to unstable or low-quality proxies. For long-term stability, choosing IPcook with verified residential and ISP proxies helps ensure reliable connections and reduces the chance of this error reappearing.

How to Fix ERR_PROXY_CONNECTION_FAILED

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