github.io

Scanned 8 days ago · Aug 11, 2026, 9:17 PM

A-

TLS & Certificate

Protocol support, cipher strength and the certificate chain, evaluated the way a browser would.

Score80%
  • the server accepts 2 weak cipher suite(s): ECDHE-RSA-AES128-SHA256, AES128-GCM-SHA256
  • no Strict-Transport-Security (HSTS) header
NegotiatedTLSv1.3, TLS_AES_128_GCM_SHA256
Forward secrecyYes
HSTSnot enabled

Protocol support

YesTLS 1.3
YesTLS 1.2
NoTLS 1.1 (deprecated)
NoTLS 1.0 (deprecated)

Cipher suites probed

Each suite below was tested with its own TLS 1.2 handshake, restricted to exactly that cipher - “accepted” means the server completed a handshake using it, not merely that it's listed as a possibility.

ECDHE-ECDSA-AES256-GCM-SHA384
SecureNot offered
ECDHE-RSA-AES256-GCM-SHA384
SecureAccepted
ECDHE-ECDSA-AES128-GCM-SHA256
SecureNot offered
ECDHE-RSA-AES128-GCM-SHA256
SecureAccepted
ECDHE-ECDSA-CHACHA20-POLY1305
SecureNot offered
ECDHE-RSA-CHACHA20-POLY1305
SecureAccepted
DHE-RSA-AES256-GCM-SHA384
SecureNot offered
DHE-RSA-AES128-GCM-SHA256
SecureNot offered
ECDHE-RSA-AES256-SHA384
WeakNot offered
ECDHE-RSA-AES128-SHA256
WeakAccepted
AES256-GCM-SHA384
WeakNot offered
AES128-GCM-SHA256
WeakAccepted
DES-CBC3-SHA
InsecureNot offered
RC4-SHA
InsecureNot offered
NULL-SHA
InsecureNot offered

Certificate

Subject*.github.io
IssuerYR2
Additional names*.github.com, *.github.io, *.githubusercontent.com, github.com, github.io, githubusercontent.com
ValidJun 4, 2026, 11:26 PM – Sep 2, 2026, 11:26 PM (expires in 22 days)
KeyRSA 2048 bit
Certificate chain4 certificate(s)
Trusted by common trust storesYes
Matches the scanned hostnameYes
Self-signedNo
F

Security Headers

The HTTP response headers browsers use to restrict what a page - or an attacker inside it - can do.

Score10%
  • no Content-Security-Policy header
  • no Strict-Transport-Security header
  • no X-Content-Type-Options: nosniff
  • no clickjacking protection (X-Frame-Options or frame-ancestors)
  • no Referrer-Policy header
  • no Permissions-Policy header
  • no Cross-Origin-Opener-Policy header
  • no Cross-Origin-Resource-Policy header
  • the Server header discloses "GitHub.com"
Content-Security-Policynot set
Strict-Transport-Securitynot set
X-Content-Type-Optionsnot set
X-Frame-Optionsnot set
Referrer-Policynot set
Permissions-Policynot set
Cross-Origin-Opener-Policynot set
Cross-Origin-Resource-Policynot set
–

Email

Whether mail delivered to this domain is protected in transit, and whether SPF/DMARC stop it being spoofed.

Scoren/a
  • no mail servers (MX records) found for this domain