SSL certificate
Definition
An SSL certificate (technically TLS nowadays) is the file that powers your site's HTTPS padlock: exchanges between your visitors and the server are encrypted. Without it, browsers display "site not secure".When a visitor fills in your contact form, their information travels between their browser and your server. The SSL certificate encrypts that journey: nobody can read or alter the data along the way. It is what displays the padlock and the "https://" in the address bar.
Its absence shows immediately: browsers mark the site "not secure", a warning that rightly scares away a good share of visitors. It is also a basic prerequisite for search visibility: engines have favoured encrypted sites for years.
Good news: basic certificates are free (the Let's Encrypt initiative issues millions of them) and renew automatically when hosting is properly managed. There is therefore no reason, technical or budgetary, to run a professional website without HTTPS.
The real point of vigilance is renewal. An expired certificate shows a warning page to all your visitors overnight. It is typically what managed hosting monitors for you, and a point we systematically check during a website migration.
Click the padlock in the address bar of your own site and check the certificate's expiry date. If nobody in the company knows who renews it, you have found a risk to fix this week.
Frequently asked questions
No: the encryption is identical. Paid certificates add administrative guarantees or extended validations, useful to certain organisations. For most professional websites, a free, properly renewed certificate is enough.
Browsers show a warning page instead of the site, and traffic drops immediately. Automatic renewal, standard with well-managed hosting, eliminates that risk.