HTTP Headers Analysis for https://circl.lu

Detected Technologies from Headers

See all in URL Inspect 3

Apache

Google Static File Front End

Google Cloud

HTTP Security Headers

Status

Strict-Transport-Security

Present

max-age=15768000

Content-Security-Policy

Basic

default-src; img-src Analyze

Content-Security-Policy-Report-Only

Missing

Not configured Analyze

X-Frame-Options

Excellent

DENY

X-Content-Type-Options

Good

nosniff

Referrer-Policy

Missing

Not configured

Permissions-Policy

Missing

Not configured

Recommendations

• Increase HSTS max-age to at least 1 year and add includeSubDomains
• Improve CSP by adding more specific directives and removing 'unsafe-inline'
• Add Referrer-Policy header (recommended: strict-origin-when-cross-origin)
• Consider adding Permissions-Policy to control browser features

Performance Headers

Accept-Ranges

Performance

bytes

Connection

Performance

close

Vary

Performance

Accept-Encoding

accept-ranges: bytes
connection: close
vary: Accept-Encoding

Caching Headers

Etag

Caching

"4778-64a6275013692"

Last-Modified

Caching

Mon, 09 Feb 2026 11:29:50 GMT

etag: "4778-64a6275013692"
last-modified: Mon, 09 Feb 2026 11:29:50 GMT

Content Headers

Content-Length

Content

18296

Content-Type

Content

text/html

content-length: 18296
content-type: text/html

Server Headers

Server

Apache

server: Apache

CORS Headers

No CORS headers found

Cookies Headers

No cookies headers found

Other Headers

Date

Other

Mon, 30 Mar 2026 04:40:43 GMT

date: Mon, 30 Mar 2026 04:40:43 GMT

Recommendations

Enable compression (gzip/brotli) to improve performance

Add Cache-Control header to optimize caching