⚠️ Disclaimer

This tool is intended solely for educational and research purposes. Do not use it to scan or access networks, systems, or devices without explicit authorization. Unauthorized scanning may violate laws or terms of service and could result in penalties or legal action. Use responsibly and only on networks you own or are permitted to test.

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ProxyChecker

A blazing-fast, epoll-based, multi-threaded proxy checker written in C++20.

• Verification model:

  • HTTP proxies: validate via HTTP CONNECT to the target (default: google.com:80 - the most reliable test host). For cleartext test services on port 80, the checker performs an HTTP GET through the proxy. When using services that return client IP (like ifconfig.io), it requires the returned public IP differs from the client's baseline IP to avoid false positives.
  • SOCKS4/5: perform CONNECT to the target; if the target is port 80, send an HTTP HEAD request

• Supports HTTP, SOCKS4, SOCKS5 with automatic retry mechanism

• Highly parallel with per-thread epoll and sharded inputs

• Conservative timeouts (5s/8s/12s) and enhanced socket tuning for reliability

Build

make -C ProxyChecker -j

Scan the Internet

Theoretically, you can scan the entire Internet searching for public proxies:

./proxychecker --range 0.0.0.0/0 --workers 12 --concurrency 100000 --timeout 20 --scan-all-ports

Usage

Basic

For a range:

./proxychecker --range 192.168.0.1/18 --out good.txt

For a list

./proxychecker --in proxies_list.txt --out good.txt

For a list of ranges

./proxychecker --range-file proxies_list.txt --out good.txt

Advanced options

# From a list file
./proxychecker --in proxies.txt --out good.txt \
  --workers 8 --concurrency 1024 \
  --test-host google.com --test-port 80 --test-path / \
  --timeout 5 \
  --default-proto http --http-mode connect

# Scan an IP range in CIDR on common proxy ports
./proxychecker --range 104.20.15.0/24 --out good_from_range.txt \
  --workers 8 --concurrency 1024 \
  --timeout 5

# Scan multiple CIDR ranges from a file
# range_list.txt (example):
# 104.28.234.240/30
# 104.28.234.244/32
# 104.28.246.42/31
# 109.224.208.0/21
# 109.238.144.0/20
./proxychecker --range-file range_list.txt --out good_from_ranges.txt \
  --workers 8 --concurrency 1024 \
  --timeout 5

# Scan all ports (1–65535) for each IP in a range
./proxychecker --range 10.0.0.0/30 --scan-all-ports --out good_full_scan.txt \
  --workers 12 --concurrency 25000 --timeout 5

# Example: scan ranges from a file across all ports with custom worker/concurrency
./proxychecker --range-file 212.txt --scan-all-ports --workers 12 --concurrency 25000 --timeout 5 --out good_full_scan_from_file.txt

# Use retry mechanism for better reliability
./proxychecker --in proxies.txt --out good.txt \
  --max-retries 2 --timeout 8

# Test all protocols even when default is specified
./proxychecker --in proxies.txt --out good.txt \
  --default-proto http --multi-protocol

# Disable strict IP masking validation (useful for Google and other hosts)
./proxychecker --in proxies.txt --out good.txt \
  --test-host google.com --disable-ip-masking

HTTP proxy validation and reliability features

When verifying HTTP proxies against test services on port 80 (default: --test-host google.com --test-port 80), the checker includes several reliability enhancements:

IP Masking Validation (for IP-returning services)

For test services that return client IP (like ifconfig.io), the checker performs enhanced validation:

• Establishes the proxy connection (HTTP CONNECT if applicable)
• Sends an HTTP GET to the test service through the proxy
• Extracts the first IPv4 address from the response body and compares it to the client's baseline public IP
• The proxy is considered valid only if the response contains an IP that differs from the baseline IP
• Supports fallback IP services (ifconfig.me, ifconfig.io, icanhazip.com, checkip.amazonaws.com) if primary service fails

Google.com Compatibility (Most Reliable Default)

Google.com is the default test host because it's the most reliable and globally available service. It doesn't return client IP, so the checker:

• Accepts any successful HTTP response (2xx/3xx) as validation
• Handles bot detection redirects gracefully
• Uses --disable-ip-masking automatically for google.com
• Provides consistent global availability and minimal downtime

Retry Mechanism

• Automatic retry with increased timeouts for failed connections
• Configurable with --max-retries N (default: 1)
• Helps handle temporary network issues and rate limiting

Example usage with enhanced reliability:

# Standard Google validation (no IP masking needed)
./proxychecker --range-file ipranges.txt \
  --workers 4 --concurrency 10000 \
  --timeout 5 --max-retries 2 \
  --out good.txt

# IP masking validation with ifconfig.io
./proxychecker --range-file ipranges.txt \
  --workers 4 --concurrency 10000 \
  --timeout 5 --max-retries 1 \
  --test-host ifconfig.io --test-port 80 \
  --out good.txt

Streaming generation for range scans

When using --range or --range-file, tasks are generated on the fly and fed through a bounded queue to worker threads. This avoids preallocating every IP/port/protocol combination in memory.

• By default, the queue capacity is workers * concurrency * 2. You can override this with --queue-size N.
• Progress is shown by IPs or ports depending on whether --scan-all-ports is used.
• This design prevents memory exhaustion when scanning large ranges or all ports (1–65535).

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Input file format:

• ip:port
• proto://ip:port where proto is http, socks4, or socks5
• Or ip:port,proto

Output file format:

• One working proxy per line in proto://ip:port format.

Range scanning:

• Use --range CIDR (e.g., 10.0.0.0/24) to enumerate all IPv4 addresses in the range and test common proxy ports: 80, 8080, 1080, 3128, 8888, 8000, 8081, 8082, 3129, 4145, 9999
• Use --range-file FILE to provide multiple CIDR ranges, one per line.
• Use --scan-all-ports to scan all ports (1–65535) for each IP instead of only common ports.
• --in, --range, and --range-file are mutually exclusive.

Real-time feedback:

• Successful proxies are printed immediately, e.g., Found: http://1.2.3.4:8080.
• A dynamic progress bar updates counts of checked, succeeded, and failed proxies.

Protocol handling and new options:

• Default behavior: If a line is ip:port without a protocol, the checker tries all supported protocols and HTTP methods for that endpoint in parallel:

  • HTTP CONNECT
  • HTTP DIRECT (absolute-form HEAD request)
  • SOCKS5 CONNECT
  • SOCKS4 CONNECT

• With --default-proto: Only the specified protocol is tested for lines without explicit protocol

• Explicit protocol: Lines with explicit protocol (http://, socks4://, socks5:// or ,proto) use only that protocol

New CLI options for enhanced control:

• --max-retries N: Maximum retry attempts for failed connections (default: 1)
• --disable-ip-masking: Disable IP masking validation (useful for Google, default for google.com)
• --strict: Enable strict validation requiring body IP for port 80 (default: enabled)
• --no-strict: Accept any 2xx response as success, disable strict validation

Notes on correctness and reliability:

• Plain web servers on port 80/443 may respond to raw HTTP but are not proxies
• The tool now uses conservative timeouts (5s/8s/12s) instead of aggressive ones for better reliability
• Reduced default concurrency (1024 vs 2048) prevents resource exhaustion under load
• Enhanced buffer management (128KB) and TCP keepalive improve connection stability
• Automatic retry mechanism handles temporary failures and rate limiting
• Google.com testing (default) provides the most reliable connectivity validation worldwide without IP masking requirements

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Repository and Build

Clean repository structure:

• Enhanced .gitignore prevents build artifacts, output files, and temporary files from being tracked
• Build artifacts (proxychecker binary, build/ directory) are automatically excluded
• Output files (*.txt, *.log) and IDE files are ignored
• Use make clean to remove all build artifacts

Build requirements:

• C++20 compatible compiler (GCC recommended)
• Linux with epoll support
• Make utility

# Clean build
make clean && make -j

# Build with custom optimization
CXXFLAGS="-O2 -g" make

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Notes

• Only numeric IPs are resolved currently to avoid DNS overhead. Add hostnames with caution
• Requires a high ulimit -n; the program attempts to raise it automatically
• Designed for Linux with epoll
• Recent improvements focus on reliability over raw speed, with conservative timeouts and retry mechanisms