What is an SSL certificate?
SSL encrypts data between visitors and your site. Here is what a certificate is, the types available, how to install one and what to check afterwards.
What is an SSL certificate?
An SSL certificate is a security layer that encrypts data between a visitor's browser and your website. The technology in use today is technically called TLS, but the name SSL remains widely used. Sites with a certificate have addresses starting with https.
Why is it necessary?
Not using SSL creates both security and trust problems:
- Information entered in forms is protected by encryption.
- Browsers mark sites without SSL as not secure.
- Visitors may leave when they see the warning.
- HTTPS is a signal Google considers in page experience.
Even for a business site with a contact form, SSL is now a basic requirement.
Types of certificate
Certificates differ by validation level:
- DV: Confirms domain ownership and suits most sites.
- OV: Also confirms company details.
- EV: Includes the most thorough company validation.
- Wildcard: Covers all subdomains.
Free certificates such as Let's Encrypt offer the same encryption strength, and many hosts install and renew them automatically.
How do you install it?
On most hosting panels, SSL is enabled in a few clicks. After installation, do the following:
- Redirect all http addresses to https.
- Update internal links and images to https.
- Check the sitemap with the new addresses.
- Check your Search Console property.
If an image on a page still loads over http, a mixed content warning can appear.
Common problems
When a certificate expires, the browser shows visitors a large warning, so make sure automatic renewal works. If you use a service such as Cloudflare, the server certificate and the service's SSL mode must match, or the site can show errors.
SSL does not solve everything
The padlock does not mean a site is completely safe. SSL only protects data in transit. Current software, strong passwords, backups and regular maintenance are part of security too.
Frequently asked questions
Is free SSL safe?
Yes. Its encryption strength is on the same level as paid DV certificates.
Does SSL slow my site?
On modern servers, the effect is very small and not noticeable.
What happens if it expires?
Browsers show visitors a security warning. Check that automatic renewal works.
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