seoPopular Client-Side Only

Security Header Checker

Check any public website's HTTP security headers (HSTS, CSP, X-Frame-Options, cookie flags, and more) in seconds.

Quick Reference & Instructions

Simple steps, pro tips, and execution details

1

Provide Inputs

Type, paste, or select your values in the form fields below.

2

Instant Live Analysis

Calculations and formatting happen automatically with zero delay as you type.

3

Copy or Use Output

Copy results or apply the clean output directly to your projects.

How It Works

Fetches the page's response headers and checks them against common security header best practices. This is a security assessment, not a penetration test - it never attempts logins, exploits, or destructive checks.

Frequently Asked Questions

Common questions about calculations, assumptions, and edge cases.

No. This tool only reads public HTTP response headers - it never attempts to log in, exploit, or scan for vulnerabilities.