cdn-detect

Identify the CDN, WAF, or bot-management vendor in front of a domain. Vendor-neutral, no API keys, no cloud account.

$ cdn-detect cloudflare.com github.com
domain:        cloudflare.com
ip:            104.16.132.229
is_cdn:        True
cdn_provider:  Cloudflare
methods:       ip_prefix, http_header

domain:        github.com
ip:            140.82.121.4
asn:           AS36459  (GITHUB)
is_cdn:        False
methods:

Why publish this? Most "what CDN is this site on?" tools either guess from a single signal (headers only, or DNS only) and miss obvious cases, or wrap a paid intel feed. cdn-detect runs four independent detection strategies — CNAME chain, IP prefix, ASN lookup, response headers, plus cookie-based bot-management fingerprints — and tells you which one fired. No registrations, no rate limits, MIT-licensed.

Install

pip install cdn-detect

Requires Python 3.10+ and outbound DNS + HTTPS.

Use

CLI:

cdn-detect example.com
cdn-detect example.com --json
cdn-detect example.com --no-http     # DNS-only, no HTTP round-trip
cdn-detect a.com b.com c.com         # multiple domains

Library:

from cdn_detect import detect

result = detect("example.com")
print(result.cdn_provider)        # 'Cloudflare', 'Akamai', None, ...
print(result.detection_methods)   # ['cname', 'http_header']
print(result.bot_management)      # 'Cloudflare Bot Management', None, ...
print(result.as_dict())           # JSON-serialisable

What it detects

Signal	What's matched	Example
CNAME chain	Vendor-owned hostnames in the resolution chain	evil.com → evil.com.cdn.cloudflare.net.
IP prefix	Hard-coded vendor IPv4 ranges	104.16.0.0/12 → Cloudflare
ASN	Origin AS number via Team Cymru DNS	AS13335 → Cloudflare
ASN org	Vendor name in AS org string	AS54113 FASTLY → Fastly
HTTP headers	Vendor-specific response headers	cf-ray:, x-amz-cf-id:, x-akamai-*
Cookies	Vendor bot-management cookies	__cf_bm, _abck, incap_ses_*
Tunnels	Reverse-tunnel and zero-trust providers	cfargotunnel.com, *.ts.net, ngrok.io

Currently knows about: Cloudflare, Akamai, Fastly, CloudFront, Imperva, Sucuri, Radware, StackPath, Edgio, Bunny CDN, KeyCDN, Reblaze, Azure Front Door / CDN, Google Cloud CDN, Vercel, Netlify, F5/Volterra, GitHub Pages — plus bot-management from Cloudflare, Akamai, Imperva, Radware, AWS WAF, PerimeterX/HUMAN, DataDome, Kasada — plus tunnels from Cloudflare, Tailscale, ngrok, Twingate, ZeroTier, Azure Dev Tunnels, and others.

Why multiple strategies

A single signal misses a lot:

• Cloudflare proxied behind another reverse proxy: HTTP headers are stripped, but ASN still resolves to AS13335.
• Akamai customer with a custom hostname: CNAME chain has no akamai.net reference, but the IP lands in 23.32.0.0/11.
• Customer behind Cloudflare Tunnel (cfargotunnel.com): the resolved IP belongs to Cloudflare, but the protection model is fundamentally different — tunnel_provider surfaces this distinction.
• Sites running an on-prem WAF that doesn't add response headers: cookies often still leak the vendor.

detection_methods lists every strategy that fired so you know how confident the verdict is.

What it doesn't do

• Doesn't enumerate every vendor IP range. The IP-prefix list is curated, not exhaustive — for production-grade matching, supplement with vendor-published feeds (Cloudflare /ips-v4, AWS ip-ranges.json, etc.).
• Doesn't probe the origin behind the CDN. That's a separate problem (and a much more invasive one). For origin-discovery, see DDactic or commercial DAST tooling.
• Doesn't try to fingerprint custom on-prem appliances by deep behavior — only by easily observable signals.

Contributing signatures

The signature data lives in src/cdn_detect/signatures.py. PRs adding new providers or expanding IP ranges are very welcome, please include a one-line citation (vendor doc, public IP feed URL, or observable example) in the PR description.

License

MIT. See LICENSE.

Maintained by

DDactic — DDoS resilience testing and external attack-surface management.