What Is an SSL Certificate? Why Is HTTPS a Must?
How encrypted connections affect trust, SEO and payment security, what types of SSL exist, and how to get rid of the not secure warning in the browser.
Aurora YazılımEditorial team
6 min read
An SSL certificate is a digital document that verifies a website's identity and ensures that the connection between the visitor and the server is encrypted. On a site with a certificate installed, the address starts with https:// and the browser shows the connection as secure. As a result, forms, passwords and payment details cannot be read or altered in transit.
What Does an SSL Certificate Do?
On an unencrypted connection, everything sent between the browser and the server travels as plain text across the networks in between. On a shared Wi-Fi network, a malicious person could see the phone number typed into a contact form or the password on a login page. An SSL certificate encrypts this traffic and makes it unreadable.
The certificate's second job is authentication. The browser uses the certificate to check that the server it is connecting to really belongs to that domain. This makes it harder for a fake server in the middle to pose as your site.
The technical name of the protocol in use today is TLS (Transport Layer Security); SSL is the name of the older versions and is no longer considered secure. Out of habit, though, the industry still says SSL certificate.
What Is HTTPS and How Does It Work?
HTTPS is the version of HTTP, the protocol that carries web pages, encrypted with TLS. When a visitor connects to the site, the browser and server perform a short handshake: the server presents its certificate, the browser verifies that it was issued by a trusted certificate authority and has not expired, and then both sides generate encryption keys that are specific to that session.
This takes milliseconds, and thanks to modern protocols the speed loss is almost nil. What is more, faster protocols such as HTTP/2 and HTTP/3 work in browsers only over HTTPS; so encryption often speeds a site up rather than slowing it down. We handle these server-side settings together in our speed and performance optimization work.
Why Is HTTPS a Must?
The Not Secure Warning
Current browsers mark pages that don't use HTTPS with a not secure warning in the address bar; the warning is even more prominent on pages with form fields. When this warning is the first thing a visitor sees, they are less likely to fill in the contact form or place an order.
SEO Impact
Google has openly announced that it uses HTTPS as a signal in search rankings. This signal does not determine rankings on its own, but a non-secure site starts behind in terms of page experience. When moving to HTTPS, connecting the old HTTP URLs to the new ones with 301 redirects preserves the search visibility you have earned; these details are part of the SEO-friendly web design process.
Payment Security
Every page that collects card details requires an encrypted connection; PCI DSS, the card industry's security standard, requires card data to be transmitted over open networks with strong encryption. When choosing an e-commerce platform, check that the certificate is valid on all pages and renews automatically.
Protection of Personal Data
Sites that collect names, phone numbers and email addresses through a contact, membership or reservation form process personal data. Encrypting data in transit is one of the basic technical measures expected. For the details of your obligations, check the current KVKK (Turkish data-protection law, comparable to GDPR) legislation and consult your legal advisor.
What Types of SSL Are There?
SSL types are separated along two axes: how thoroughly the issuer verifies you, and how many domains the certificate covers. Encryption strength is the same in all types; the difference lies in the level of validation and the scope.
| Type | What is validated | Best suited for |
|---|---|---|
| DV (Domain Validation) | Only that the domain belongs to you | Blogs, corporate sites, most small stores |
| OV (Organization Validation) | The domain and the company's official registration | Businesses that want their corporate identity shown in the certificate |
| EV (Extended Validation) | Comprehensive company validation | Fields that require a high level of trust, such as banking and finance |
Certificates by Coverage
Browsers used to highlight EV certificates with the company name in the address bar; in current browsers this visual difference has largely been removed. For this reason, a well-configured DV certificate is enough for most sites.
- Single domain: only yourcompany.com and usually the www version.
- Wildcard: in the form *.yourcompany.com, all subdomains at the same level (shop, panel, blog).
- Multi-domain (SAN): combines different domains in a single certificate; practical for businesses with more than one brand.
Free or Paid?
Non-profit certificate authorities such as Let's Encrypt provide free DV certificates, and these have the same encryption strength as paid DV certificates. They are issued with a short validity period and work smoothly with automatic renewal tools. Many hosting panels and CDN services install this certificate with one click.
Paid certificates make sense for needs such as OV and EV validation, insurance and support from some providers, and long renewal intervals on legacy systems where automation is not possible. The price is determined by the validation type, the number of domains covered and the certificate authority.
Checklist After Installing the Certificate
Installing the certificate is only half of the job. Until the steps below are done, the site may still show warnings or your search visibility may suffer. We explain the server installation steps separately in our SSL certificate installation guide.
- Turn all HTTP requests into HTTPS with a permanent (301) redirect.
- Make sure images, scripts and style files on your pages are not loaded over http://; otherwise a mixed content warning appears.
- Update the sitemap, canonical tags and internal links to HTTPS URLs.
- Check in Search Console that the HTTPS version is verified.
- If everything runs smoothly, use the HSTS header to tell browsers to connect to the site only over HTTPS.
- Set up an alert that monitors the certificate's expiry date.
Common SSL Errors
Taking a current copy of the site and database before changing certificate and server settings lets you roll back within minutes if something goes wrong; the methods are in the how to back up article. If you are curious about the future of encryption, our post-quantum cryptography article explains how TLS will change in the coming years.
| Mistake | Why | Fix |
|---|---|---|
| Certificate expired | Renewal was not done | Renew the certificate and set up automatic renewal |
| Name mismatch | The certificate does not cover www or the subdomain | Get a certificate that covers all addresses |
| Your connection is not private | Missing intermediate certificate chain | Install the full certificate chain on the server |
| No lock icon, a warning instead | Mixed content | Change resources loaded over http:// to https:// |
| Device clock is wrong | A visitor-side issue | Correct the device's date and time settings |
Frequently Asked Questions
01Does an SSL certificate slow down the site?
In modern TLS versions the handshake takes very little time, and session reuse lowers the cost even further for repeated connections. Because HTTP/2 and HTTP/3 work only over HTTPS, an encrypted site often loads faster.
02Is SSL on the payment page alone enough?
No. Browsers evaluate every page separately and show a warning on unencrypted pages. Login cookies can also leak through unencrypted pages. Serving the entire site over HTTPS is standard practice today.
03Do I need a separate certificate for my subdomains?
A single-domain certificate covers only the names listed. If you have several subdomains, you can use a wildcard certificate or a separate free certificate for each subdomain. Once automatic renewal is set up, both are practical solutions.
04How do I know my certificate is installed correctly?
Click the lock icon in the browser to see who the certificate was issued to and its expiry date. For a more detailed check, online SSL test tools report the certificate chain, protocol versions and configuration weaknesses.
An SSL certificate is no longer an option but a prerequisite for trust, search visibility and online payments; with correct installation and automatic renewal, you can set it up once and forget about it. To handle HTTPS, server and cache settings together, take a look at our speed and performance optimization service, and for a site that considers search visibility from the start, our web design page; for any questions, write to us.
