HTTP Headers Analysis for https://api.fastmail.com

Detected Technologies from Headers

See all in URL Inspect 4

Cloudflare NEL Monitoring

Gravatar

Cloudflare CDN

Libsyn

HTTP Security Headers

Status

Strict-Transport-Security

Excellent

max-age=31536000; includeSubDomains; preload

Content-Security-Policy

Basic

default-src; script-src; style-src; +5 more Analyze

Content-Security-Policy-Report-Only

Missing

Not configured Analyze

X-Frame-Options

Excellent

DENY

X-Content-Type-Options

Good

nosniff

Referrer-Policy

Good

strict-origin-when-cross-origin

Permissions-Policy

Present

accelerometer=(), ambient-light-sensor=(), battery=(); +17 more

Recommendations

• Improve CSP by adding more specific directives and removing 'unsafe-inline'

Performance Headers

Connection

Performance

close

Transfer-Encoding

Performance

chunked

connection: close
transfer-encoding: chunked

Caching Headers

Cache-Control

Caching

public, max-age=0, must-revalidate

Etag

Caching

"a792c4c4dec029fcbf5dc425246d07a8"

cache-control: public, max-age=0, must-revalidate
etag: "a792c4c4dec029fcbf5dc425246d07a8"

Content Headers

Content-Type

Content

text/html; charset=utf-8

content-type: text/html; charset=utf-8

Server Headers

Server

cloudflare

server: cloudflare

CORS Headers

Access-Control-Allow-Origin

Cors

*

access-control-allow-origin: *

Cookies Headers

Set-Cookie

Cookies

set-cookie: campaign=developer-homepage%3A1775661159%3Adeveloper%3A1775661158%3Ahomepage%3A1775661158%3A3; Domain=fastmail.com; Path=/; SameSite=Lax; Max-age=31536000; Secure;

Other Headers

Accept-Ch

Other

Sec-CH-UA-Arch, Sec-CH-UA-Bitness

Alt-Svc

Other

h3=":443"; ma=86400

Cf-Ray

Other

9e923623eb831741-IAD

Date

Other

Wed, 08 Apr 2026 15:12:39 GMT

Nel

Other

Report-To Group cf-nel max-age: 1w

success: 0.0%

Report-To

Other

Group cf-nel max-age: 1w

Endpoint 1 https://a.nel.cloudflare.com/report/v4?s=WkXK%2FO96Zr6xrzmCHxqSSt4XAN95pyGwg17V3lRMg3bhu2zuV7pqTZIp0IpqEMW7bhrtq6s8rjPLr81GPOLzPIgCReBBFv8aSfu41sAPD7T1lsyGkmeZwz3reW5wd6cmAuRW

accept-ch: Sec-CH-UA-Arch, Sec-CH-UA-Bitness
alt-svc: h3=":443"; ma=86400
cf-ray: 9e923623eb831741-IAD
date: Wed, 08 Apr 2026 15:12:39 GMT
nel: {"report_to":"cf-nel","success_fraction":0.0,"max_age":604800}
report-to: {"group":"cf-nel","max_age":604800,"endpoints":[{"url":"https://a.nel.cloudflare.com/report/v4?s=WkXK%2FO96Zr6xrzmCHxqSSt4XAN95pyGwg17V3lRMg3bhu2zuV7pqTZIp0IpqEMW7bhrtq6s8rjPLr81GPOLzPIgCReBBFv8aSfu41sAPD7T1lsyGkmeZwz3reW5wd6cmAuRW"}]}

Recommendations

Enable compression (gzip/brotli) to improve performance