How to fix hsts disabled on PrestaShop

Steps for PrestaShop

1. In PrestaShop Admin, go to Shop Parameters → General and enable 'Force HTTPS for all pages' — this enables redirects but does not itself set the HSTS header.
2. Add the HSTS header at the server level: for Nginx add `add_header Strict-Transport-Security "max-age=31536000; includeSubDomains" always;` in your server block; for Apache add `Header always set Strict-Transport-Security "max-age=31536000; includeSubDomains"` in your VirtualHost or .htaccess.
3. Alternatively, add it in PrestaShop's .htaccess file in the root directory (Apache only), after the existing security headers section.
4. Verify via browser DevTools after deployment.

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

What is hsts disabled?

HTTP Strict-Transport-Security (HSTS) is a security header your web server sends to a visitor's browser. It tells the browser: "For the next X seconds, never connect to this site over plain HTTP — always use HTTPS, no exceptions." When HSTS is disabled or set to `max-age=0`, that instruction is removed and the browser is free to make unencrypted HTTP requests. HSTS is a one-line server response header, not a code change, but it has a significant impact on how securely shoppers connect to your store.

Without HSTS, even if your store has an SSL certificate, a customer could still land on an unencrypted HTTP version of your site — either by typing your address without "https://" or by following an old link. That window is enough for an attacker on the same network (e.g. a coffee-shop Wi-Fi) to intercept login credentials, session cookies, or payment-related data in a "man-in-the-middle" attack. Google treats HTTPS as a ranking signal and flags insecure sites in Chrome, so a missing or zeroed-out HSTS header can hurt both your search rankings and customer trust. Regulations such as PCI-DSS (required for stores handling card data) explicitly expect transport-layer protections like HSTS to be in place, and failure to comply can result in fines or loss of the ability to accept card payments.

See the complete Hsts disabled guide for every platform and the full background.