Free COOP Header Checker
Check Cross-Origin-Opener-Policy for cross-window isolation and security.
Enable safer browsing contexts and isolation for modern web features.
- COOP header check
- Cross-window isolation
- Best-practice values
"Barrion's security scanning has helped us implement best security practices efficiently, saving us countless hours."
Sarah Chen
Head of Security
"We identified and fixed critical vulnerabilities before our platform launch, saving us from potential data breaches."
Marcus Anderson
CTO
"Barrion gives us peace of mind, knowing we're notified of any security issues. Exactly what our team needed."
Oskar Nilsson
Tech Lead
Scan in three simple steps
Fast, safe, non-intrusive checks with actionable results.
Start scan
Enter your URL, and click the start scan button to begin.
Scan runs
Barrion performs passive, read-only security checks with minimal site impact.
View results
See security findings with prioritized, actionable recommendations.
What is COOP?
COOP isolates your top-level window from other origins by controlling cross-window interactions, reducing XS-Leaks and enabling cross-origin isolation.
Recommended values
- Cross-Origin-Opener-Policy: same-origin
- Use with COEP and CORP for isolation
Tool-specific questions
Do I need COOP without COEP?
Will COOP break popups?
Why Choose Barrion?
Real-Time Results
Instant security analysis with detailed reports, giving you an immediate security overview
Comprehensive Checks
Multiple best-practice security checks in a single scan, for broad coverage
Actionable and Effective
Clear recommendations for fixes, helping you improve your security quickly and effectively
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