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Technical SEOReviewed September 5, 2026

What is SSL Certificate?

Secure Sockets Layer Certificate

An SSL certificate is a small data file installed on a web server that proves a site's identity and encrypts the connection between the site and its visitors, turning http:// into https://.

How it works

When someone visits your site, their browser checks the certificate and sets up an encrypted connection. Anything they send, like form details or payment info, travels scrambled so others on the network can't read it. Today the technology is technically called TLS, but most people still say SSL.

What visitors see

Browsers show HTTPS sites normally, while Chrome and other browsers label plain HTTP pages as 'Not secure'. That warning can scare visitors away, especially on pages with forms.

Getting one

Many hosting companies include free certificates, often from Let's Encrypt, and renew them automatically. Paid certificates add extra identity checks, which some larger businesses prefer, but most small sites do fine with a free one.

Why SSL Certificate matters

HTTPS protects your visitors' information, avoids browser warnings and is expected by customers. Google has also used HTTPS as a ranking signal for years, so a site without it starts at a disadvantage.

The warning that cost leads

A contractor's quote form sat on an HTTP page, so Chrome flagged it 'Not secure'. After the site moved to HTTPS with a free certificate and old links were redirected, form submissions picked up again.

Common mistakes

  • Letting it expire

    An expired certificate triggers scary full-page warnings. Use automatic renewal and monitor expiry dates.

  • Mixed content

    An HTTPS page that still loads some images or scripts over HTTP can show warnings. Update every asset to HTTPS.

  • No redirects from HTTP

    After switching, redirect all HTTP URLs to their HTTPS versions so visitors and search engines land on the secure pages.

Where we work on this

Applied, not theoretical

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