cURL

This guide explains how to use Squid Proxies with cURL, a powerful command-line tool used for making HTTP requests. Whether you're testing your proxy pool, performing lightweight API checks, or troubleshooting sessions, cURL is a fast and reliable way to validate proxy connectivity.

When to Use cURL with Squid Proxies

• Quick proxy validation (before integrating into code)
• Checking outbound IP visibility
• Inspecting headers and response behavior
• Debugging proxy errors (403, 407, timeout, etc.)

Proxy Authentication Methods Overview

Squid Proxies supports two authentication methods:

1. IP Whitelisting

• Add your IP in the dashboard.
• Use proxies in the format: http://proxy_ip:port

2. Username/Password Authentication

• Use this format in cURL: http://username:password@proxy_ip:port

📌 Tip: Use the exact proxy address provided in your dashboard (IP or hostname).

Basic Proxy Setup in cURL

1. IP Whitelisted Proxies

curl -x http://123.456.789.10:3128 https://api.ipify.org

2. Username/Password Proxies

curl -x http://username:password@123.456.789.10:3128 https://api.ipify.org

3. Using HTTPS Proxies with --proxy and --proxy-user

curl --proxy https://proxy.squidproxies.com:8907 --proxy-user username:password https://api.ipify.org

Verifying IP Address & Headers

Check if proxy is masking your IP:

curl -x http://username:password@proxy:port https://httpbin.org/ip

Inspect full headers:

curl -x http://username:password@proxy:port https://httpbin.org/headers

Troubleshooting Common Proxy Errors

User-Agent & Custom Headers Setup

curl -x http://username:password@proxy:port \
  -A "Mozilla/5.0 (Windows NT 10.0; Win64; x64)" \
  -H "Accept-Language: en-US" \
  https://httpbin.org/headers

You can rotate headers with a script or manually emulate browser behavior.

Best Practices for cURL Proxy Usage

• Add -L to follow redirects
• Use -v or --trace to debug the request step-by-step
• For SSL-heavy testing, add --insecure (in non-production tests)
• Combine cURL with bash loops to test multiple proxies

Bash Script Example for Bulk Proxy Testing

#### !/bin/bash

while read proxy; do
  echo "Testing $proxy"
  curl -x "http://$proxy" -m 5 https://api.ipify.org
  echo -e "\n---"
done < proxies.txt

proxies.txt should contain one proxy per line like:
username:password@ip:port

Key Takeaways

cURL is an essential tool for validating and debugging proxy performance with Squid Proxies. Whether you're testing IP visibility, rotating headers, or diagnosing issues, cURL gives you full control over the request pipeline.

📞 Need help with complex testing scenarios? Contact Support — we speak developer.

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More Guides:

• Proxy Rotation & Session Management
• Custom Headers & Fingerprinting