Overview
Findings
Actions
Details
Related
A
95 / 100

opensea.io

Security report · Scanned February 18, 2026

Checks
8
Passed
7
Warnings
1
Critical
0
AI-Generated Summary
What this means

opensea.io scored 95/100, demonstrating a strong security posture. Minor improvements are noted below.

Positive signals: DNS Configuration, Known Breaches, TLS Configuration all passed.

1 action item identified, including 0 critical. The issues are configuration gaps, not architectural problems. A focused remediation effort of 2–5 days could address all findings.

How opensea.io compares

Grade distribution across 2378 companies we've scanned. opensea.io scores better than 96% of them.

96th percentile
0 Percentile rank 100
71
A+
22
A
180
A-
181
B+
69
B
333
B-
111
C+
111
C
295
C-
110
D+
92
D
216
D-
587
F
opensea.io — Grade A (95/100) 2378 companies scanned
Security checks

Each check inspects a different part of opensea.io's public security setup. Green means healthy, yellow needs attention, red is a problem.

HSTS Header
HSTS present but max-age is low (15552000s). Recommended minimum: 15768000 (6 months).
Needs work
DNS Configuration
Strengths: 2 nameservers configured (arch.ns.cloudflare.com., nicole.ns.cloudflare.com.); 5 MX records present; DNSSEC enabled; Zone transfers properly restricted.
Healthy
Known Breaches
No known breaches found in public disclosure databases.
Healthy
TLS Configuration
TLSv1.3 negotiated with TLS_AES_256_GCM_SHA384 (256-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
Healthy
Security Headers
4/5 security headers present. Missing: CSP.
Healthy
CVE Exposure
Detected technologies: cloudflare. (cloudflare detected but excluded from CVE matching — upstream infrastructure). All detected technologies are upstream CDN/proxy infrastructure. No application-level software versions exposed.
Healthy
DMARC / Email Security
Strengths: DMARC policy set to reject (strongest); SPF record present with hard-fail (-all); DKIM configured (selectors: google, s1, s2, zendesk1, zendesk2, smtpapi).
Healthy
Certificate Hygiene
Strengths: Certificate valid, 78 days remaining; Issued by Google Trust Services.
Healthy
Recommended actions
1 item

Steps to improve opensea.io's security grade, ranked by impact.

1
Increase HSTS max-age duration
Impact: < 30 Minutes
MEDIUM
HSTS is enabled but the max-age (0s) is below the recommended minimum of 15768000s (6 months). A short max-age means browsers forget the HTTPS-only policy quickly, reducing protection between visits.
Compliance impact
PCI-DSS 4.0Req 6.4.1
Application security header configuration
How to fix this
1
Update header: Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
2
Verify: curl -sI https://opensea.io | grep -i strict
At a glance

Key data points from the scan.

TLS Version
TLSv1.3
TLSv1.3 negotiated with TLS_AES_256_GCM_SHA384 (256-bit). Strong configuration with no deprecated protocols or weak ciphers detected.
DMARC Policy
p=reject
Strengths: DMARC policy set to reject (strongest); SPF record present with hard-fail (-all); DKIM configured (selectors: google, s1, s2, zendesk1, zendesk2, smtpapi).
SPF Record
Present
v=spf1 include:_spf.google.com include:mailgun.org include:_spf.atlassian.net include:mail.zendesk.c
Security Headers
4/5 present
Missing: CSP
HSTS
Not enabled
HSTS present but max-age is low (15552000s). Recommended minimum: 15768000 (6 months).
SSL Certificate
Valid
Strengths: Certificate valid, 78 days remaining; Issued by Google Trust Services.
DNSSEC
Enabled
Strengths: 2 nameservers configured (arch.ns.cloudflare.com., nicole.ns.cloudflare.com.); 5 MX records present; DNSSEC enabled; Zone transfers properly restricted.