Open
Cached
·
just now
17
Headers
HTTP Security Headers
Status
Strict-Transport-Security
Missing
Not configured
Content-Security-Policy
Missing
Not configured
X-Frame-Options
Good
SAMEORIGIN
X-Content-Type-Options
Missing
Not configured
Referrer-Policy
Missing
Not configured
Permissions-Policy
Missing
Not configured
Recommendations
- • Add Strict-Transport-Security header with max-age of at least 1 year
- • Add Content-Security-Policy header to prevent XSS attacks
- • Add X-Content-Type-Options: nosniff
- • Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
- • Consider adding Permissions-Policy to control browser features
Performance Headers
1 headers
Connection
Performance
keep-alive
Caching Headers
3 headers
Cache-Control
Caching
no-store, no-cache, must-revalidate, proxy-revalidate
Expires
Caching
0
Pragma
Caching
no-cache
Content Headers
2 headers
Content-Length
Content
10388
Content-Type
Content
text/html; charset=UTF-8
Server Headers
2 headers
Server
Server
duo-api
X-Runtime
Server
0.08254
CORS Headers
0 headers
No CORS headers found
Cookies Headers
1 headers
Set-Cookie
Cookies
wuuid=ec7b67a8-2144-4352-acb9-edfc09b645dc
Other Headers
7 headers
Date
Other
Fri, 07 Nov 2025 04:34:32 GMT
No-Retry
Other
1
Surrogate-Control
Other
no-store
X-Duo-Request-Host
Other
www.duolingo.com
X-Envoy-Upstream-Service-Time
Other
84
X-Tid
Other
ffff4176690d75650d18
X-Ws
Other
UK
Recommendations
Enable compression (gzip/brotli) to improve performance
Analysis completed in 183ms