HSTS Preload Generator - Free Online HSTS Header Generator for Secure Websites

HSTS Preload Generator - Secure Your Site with HTTP Strict Transport Security

HSTS (HTTP Strict Transport Security) is a powerful security feature that tells web browsers to always connect to your site using HTTPS, protecting users from protocol downgrade attacks and cookie hijacking. Enabling HSTS with preload goes one step further by allowing your domain to be included in the HSTS preload list maintained by major browsers like Chrome, Firefox, and Edge — ensuring your site is always served securely, even on the first visit.

Our HSTS Preload Generator helps you easily generate a valid HSTS header that meets the requirements for submission to the preload list. No need to write headers manually — just select your options and copy the result.

What Is HSTS Preload?

HSTS Preload is a browser-level mechanism where your domain is hardcoded into the browser's list of sites that should always use HTTPS — before any connection is made. This eliminates the vulnerability of the initial HTTP request and guarantees that your site is never accessed over an insecure connection.

Benefits of Using HSTS and Preload

  • ✅ Forces HTTPS: Ensures all communication between the browser and server is encrypted.

  • ✅ Blocks Insecure Access: Stops users from accessing your site via HTTP, even by mistake.

  • ✅ Improves SEO: Google favors secure websites in its ranking algorithms.

  • ✅ Protects First-Time Visitors: HSTS preload stops MITM attacks from the very first visit.

  • ✅ Easy to Implement: A single response header does the job.

Requirements for HSTS Preload

To submit your site to the HSTS preload list, your header must meet these conditions:

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

Conditions:

  1. max-age must be at least 31536000 seconds (1 year).

  2. Must include includeSubDomains.

  3. Must include the preload directive.

  4. HTTPS must be enabled across your entire site and all subdomains.

  5. You must serve this header on all HTTPS responses.

Features of the HSTS Preload Generator Tool

  • 🔒 Easy Header Generation — Generate a valid HSTS header with a few clicks.

  • ⚙️ Max-Age Control — Customize the max-age value (in seconds).

  • 🧩 Preload Toggle — Enable or disable the preload directive.

  • 🌐 IncludeSubDomains Option — Secure your entire domain and all subdomains.

  • 📋 Copy to Clipboard — One-click copy for easy server implementation.

  • 📱 Responsive Design — Works on both desktop and mobile.

How to Use the HSTS Preload Generator

  1. Set Max-Age: Choose how long browsers should remember to force HTTPS (e.g., 31536000 seconds = 1 year).

  2. Toggle IncludeSubDomains: Recommend enabling to secure all subdomains.

  3. Enable Preload: Required for submission to the HSTS preload list.

  4. Generate Header: Click “Generate HSTS Header” to get your result.

  5. Copy & Add to Server: Paste the header into your web server config (Apache, Nginx, etc).

Example HSTS Header Generated

Strict-Transport-Security: max-age=31536000; includeSubDomains; preload

Add this to your:

✅ Nginx (inside server block):

add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

✅ Apache (inside .htaccess or VirtualHost):

Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains; preload"

Conclusion

Enabling HSTS with preload is one of the strongest ways to enforce HTTPS and secure your website from downgrade attacks. With our HSTS Preload Generator, you can quickly generate a compliant header that’s ready to deploy and submit to the HSTS preload list. Secure your site — and your users — in just a few seconds.