How to fix missing x frame options on Squarespace

Steps for Squarespace

1. Squarespace does not allow direct HTTP response header customization from the admin panel.
2. Place your Squarespace site behind Cloudflare by pointing your domain's nameservers or DNS A/CNAME records to Cloudflare (in 'DNS only' mode if full proxy is preferred).
3. In Cloudflare: Rules → Transform Rules → Response Header Modification → Add header: X-Frame-Options = SAMEORIGIN for all requests → Deploy.
4. Verify by loading any Squarespace page and checking Response Headers in browser DevTools.

What is missing x frame options?

The X-Frame-Options header is a security instruction your web server sends to browsers telling them whether your pages are allowed to be loaded inside an iframe (an invisible "frame" embedded in another website). When this header is missing, any website in the world can silently embed your store inside their page. The two safe values are DENY (no framing at all) and SAMEORIGIN (only your own domain can frame your pages). Most stores should use SAMEORIGIN unless you have no legitimate need to embed your own pages in iframes, in which case DENY is even stronger.

Without X-Frame-Options, attackers can use a technique called "clickjacking" — they overlay your store's checkout or login page inside an invisible iframe on a malicious site, tricking shoppers into clicking buttons they can't see. This can lead to unauthorized purchases, stolen account credentials, or fraudulent transactions, directly costing you revenue and eroding customer trust. Search engines and security scanners flag this missing header as a vulnerability under OWASP A05:2021 (Security Misconfiguration), which can affect your site's security rating and enterprise buyer trust. Many payment card industry (PCI DSS) compliance checklists also require it, so missing it can jeopardize your ability to process card payments.

See the complete Missing x frame options guide for every platform and the full background.