--- title: "Website security grade: free security headers, SSL and email check | PostCliq" description: "Grade your website’s security headers with Mozilla HTTP Observatory scoring, check the SSL certificate expiry, and test SPF and DMARC email spoofing protection. Free, in seconds." url: "https://postcliq.com/free-tools/website-security-grade" --- [Free tools](https://postcliq.com/free-tools) · Instant check # Grade my website security Headers, certificate, email. Type your website. We grade its security headers with Mozilla’s own HTTP Observatory scoring, check its certificate, and check whether other people can send email that looks like it came from your domain. Free No sign-up Answer in seconds Three ordinary page requests and two public DNS questions. Nothing is sent to Mozilla, so the check does not appear in Mozilla’s public scan history. The free plan ## One check is a clue. The free plan is the whole picture. - A full audit of up to 50 pages, every week - The three fixes that win the most enquiries, with the evidence - Speed, security, AI visibility, tracking and the enquiry path in one report - Connect Google Analytics, Search Console and Clarity to see what visitors really do - One website free, or five client sites for an agency. No card. **Free** No card. No trial that runs out. [Create your free account](https://postcliq.com/login?mode=signup) [Already have an account? Log in](https://postcliq.com/login) ## Questions people ask Is this the same grade as Mozilla’s Observatory? It runs Mozilla’s own open-source scoring on the responses we fetch. Two small differences: we do not carry Chrome’s HSTS preload list, and we test CORS with a normal request instead of a preflight. Does a good grade mean my site is secure? No. Headers protect visitors from common browser attacks. They say nothing about out-of-date plugins, weak passwords or the server itself. A low grade is still worth fixing because it is usually an hour’s work. What are SPF and DMARC? Two DNS records that tell other mail servers which senders are allowed to use your domain. Without them, anyone can send an invoice that looks like it came from you. ## More instant checks [**What is this site built with?** See the platform behind any website, with the proof. Run it free](https://postcliq.com/free-tools/what-cms-is-this-site) [**Where is this site hosted?** Find the host, the CDN and who runs the DNS and email. Run it free](https://postcliq.com/free-tools/where-is-this-site-hosted) [**Can AI see your page?** See what ChatGPT and Claude actually read on your page. Run it free](https://postcliq.com/free-tools/can-ai-see-your-page) [**Which AI crawlers can read my site?** See which of 20 AI bots your site lets in. Run it free](https://postcliq.com/free-tools/ai-crawler-access-checker) [**Can an AI agent read my site?** Score how ready your site is for AI agents, out of 100. Run it free](https://postcliq.com/free-tools/can-ai-agents-read-my-site) [**Is my website slow?** Find the nine things that most often slow a page down. Run it free](https://postcliq.com/free-tools/website-speed-test) [**Can visitors contact you?** Check the path from visit to enquiry, step by step. Run it free](https://postcliq.com/free-tools/can-visitors-contact-you) [**Is my tracking installed?** See which analytics and ad tags are on the page. Run it free](https://postcliq.com/free-tools/is-my-tracking-installed) [**How does my page look in Google?** See your Google result and LinkedIn card before others do. Run it free](https://postcliq.com/free-tools/google-and-social-preview) [**Check my structured data** Find broken structured data and what Google can’t read. Run it free](https://postcliq.com/free-tools/schema-markup-checker) [**Do my redirects work?** Check every version of your address lands in one place. Run it free](https://postcliq.com/free-tools/redirect-checker) ## Stop guessing. See what stops visitors enquiring. Create your free PostCliq account and get your full website audit in minutes. [Sign up free](https://postcliq.com/login?mode=signup) [Log in](https://postcliq.com/login)