SSL Certificates Explained: What They Are & How to Install

If you’ve ever wondered what that padlock icon in your browser’s address bar actually means — or why your browser screams “Not Secure” at visitors who land on an HTTP site — this guide is for you. SSL certificates sit at the foundation of web security, and understanding them is no longer optional for anyone running a website.

What Is an SSL Certificate?

SSL (Secure Sockets Layer) and its successor TLS (Transport Layer Security) certificates provide powerful protection, ensuring the privacy and integrity of online communication. Despite the name “SSL” sticking around in everyday language, the modern protocol is actually TLS — but the industry still broadly calls these certificates SSL certificates.

TLS/SSL certificates are two things. First, they provide a secure connection between a website by encrypting the data that is passed between users and the domain. Second, they verify the ownership and identity of the business or person that owns the URL.

In practical terms: when a visitor submits a contact form, enters a password, or checks out in your shop, SSL encrypts that data in transit so it cannot be intercepted. Without these certificates, data could easily be exposed while in transit, increasing vulnerability to breaches and other cybersecurity concerns.

Why Every Website Needs an SSL Certificate

1. Browser Trust Warnings Drive Visitors Away

Google Chrome and other major browsers label any HTTP page as “Not Secure.” Depending on what type of site you have, this may cause visitors to leave. If you request email details or have a shop that takes payment, the lack of SSL certification is likely to mean that visitors won’t trust your site and will navigate away. Even purely informational sites suffer: non-savvy visitors may think the site is broken or hacked and quickly click away.

2. SSL Is a Google Ranking Signal

Search engines like Google have been using HTTPS as a ranking signal since 2014, and its importance has continued into recent years. It’s worth being clear-eyed about what this means: HTTPS is not a factor in deciding whether or not to index a page at all. Google does use HTTPS as a lightweight ranking factor, and having HTTPS is great for users. A free certificate from Let’s Encrypt works just as well. In other words, the type of SSL certificate you choose doesn’t move the needle on rankings — having any valid certificate does.

Google has confirmed that if all other ranking factors are similar, having HTTPS can be the tie-breaker — the ranking factor that pushes your website above a competitor. In a competitive landscape, that’s not a signal you want to give away for free.

3. Data Security and User Trust

More than 80% of online users prefer accessing information from SSL-encrypted sites. That means websites without SSL are likely to lose 80% of their potential web traffic. Such sites may also experience a high exit rate, which increases bounce rate and carries a negative SEO impact.

4. HTTPS Adoption Is Now the Norm

HTTPS adoption is nearly universal: about 88% of websites now use SSL/TLS, up from under 20% in 2018. Google reports that over 95% of page loads on Chrome were over HTTPS by early 2025, meaning almost all major sites are secure. Running a site without an SSL certificate today puts you in a small — and shrinking — minority that browsers actively flag to users.

Types of SSL Certificates: DV, OV, and EV

The level of trust and assurance provided by an SSL certificate largely depends on the validation process conducted by Certificate Authorities (CAs). These authorities play a critical role in establishing trust on the internet by verifying the identities of entities seeking SSL certificates. There are three primary validation levels to know.

Domain Validation (DV)

Domain Validation (DV) is the lowest level of validation, and verifies that whoever requests the certificate controls the domain that the certificate protects. Validation is confirmed via a DNS record or a file placed on the domain, and the certificate can be issued in minutes to hours. Cost runs from free (Let’s Encrypt) to around $100/year.

A DV SSL still provides full encryption — the browser shows a padlock. It is ideal for blogs, personal sites, portfolios, or any site that does not handle sensitive data. Let’s Encrypt alone has issued over a billion free DV certificates and holds about 63.7% of the SSL market share.

Organization Validation (OV)

Representing a valuable middle ground between DV and EV, Organization Validation certificates go beyond simple domain ownership verification to confirm the identity of the organization seeking the certificate. To verify the organization’s identity, the CA may check government databases or business directories, along with contact information such as the organization’s physical address to confirm it is a legally registered business.

OV SSL verifies domain control plus business identity and legal existence, is issued in 1–3 days, and displays verified organization details inside the certificate. OV SSL certificates offer a solid, budget-friendly solution ideal for many small businesses and nonprofit organizations looking for reliable security without overcomplicating the process.

Extended Validation (EV)

Extended validation (EV) certificates provide the maximum amount of trust to visitors, and also require the most effort by the CA to validate. With EV, nine additional verification steps are required including verifying a business’s public phone number, length of time in business, registration number and jurisdiction, a domain fraud check, contact blacklist check, and a telephone call to authenticate the employment status of the requestor.

Because they provide the maximum amount of trust, EV certificates are often preferred for entities that need to process financial transactions or sensitive data — such as online banking websites, e-commerce stores, or government databases. EV checks are so thorough that EV certificates can take days or even weeks to issue and carry the highest price of all SSL types.

Coverage Types: Single Domain, Wildcard, and Multi-Domain

Beyond the validation level, you also need to match the certificate to the scope of what you’re securing:

• Single Domain: Designed to secure a single domain such as example.com. Ideal for websites that only have one primary domain and do not require protection for subdomains.
• Wildcard: Covers all subdomains under one domain (e.g., *.example.com), though the CA still only validates control of the main domain name.
• Multi-Domain (SAN): Designed to secure multiple domains and subdomains on a single certificate. Multi-domain SSL offers more flexibility, as you can reissue the SSL and change the domains covered, and it can provide cost savings compared to purchasing individual certificates for each domain.

How to Get and Install an SSL Certificate

Prior steps include generating a Certificate Signing Request (CSR) and choosing the right SSL type, while post-installation actions focus on testing, monitoring, and renewal. Here’s the practical path from start to finish.

Step 1: Generate a Certificate Signing Request (CSR)

Certificate signing requests (CSRs) play a critical role in the early stages of the SSL certificate lifecycle, including request, enrollment, and issuance. These must be created and submitted at the beginning of the process — without them, installation will not be possible. These encrypted messages contain crucial information about the individuals or organizations who seek SSL/TLS certificates.

On most Linux servers, you generate a CSR using OpenSSL from your terminal:

openssl req -new -newkey rsa:2048 -nodes -keyout yourdomain.key -out yourdomain.csr

You’ll be prompted for your domain name, organisation details, and location. Keep the generated .key file safe — the private key must be the same one you created and used to generate the CSR. You cannot use any other private key with the signed certificate. They are inextricably linked.

Step 2: Obtain Your Certificate

For a free DV certificate, use Let’s Encrypt via Certbot. Here’s a quick overview of how to get a free SSL certificate from Let’s Encrypt using the Certbot tool: connect to your server over SSH using the IP address, username, and password; visit the Certbot website and choose your server operating system and software; follow the instructions given for your server; run any commands listed to install dependencies; run the commands to install Certbot; then run the commands listed to generate the certificate.

For a paid OV or EV certificate, submit your CSR to a trusted CA (DigiCert, Sectigo, Comodo, etc.). After you create a CSR and purchase a certificate, the validation team validates and processes your certificate request. Once validated, they issue your SSL certificate and send it to you via email.

Step 3: Install the Certificate on Your Server

The SSL installation process can play out differently with various services and platforms. You’ll want to follow server-specific instructions to ensure that the certificate is installed correctly. Here are the two most common environments:

Apache: Copy your certificate files and the CA bundle to your server, then open your Apache SSL <VirtualHost> block — Apache’s main configuration file is typically named httpd.conf or apache2.conf, found in /etc/httpd/ or /etc/apache2/. Update the SSLCertificateFile, SSLCertificateKeyFile, and SSLCertificateChainFile directives to point to your new files, then restart Apache.

Nginx: Use the command cat domain_com.crt domain_com.ca-bundle > ssl-bundle.crt to concatenate the certificate file and the CA bundle. Next, store the bundle and the private key in the relevant Nginx SSL folder. Consider using OCSP Stapling to boost the SSL handshake speed.

When you install an SSL certificate on a server, you’ll also need to install an intermediate certificate. This intermediate certificate establishes the trust of your SSL certificate by tying it to your Certificate Authority’s root certificate.

Step 4: Force HTTPS and Check for Mixed Content

Installing the certificate is only half the job. You need to redirect all HTTP traffic to HTTPS and eliminate any “mixed content” (HTTP resources loading on an HTTPS page). Best practices after installation:

1. Set up 301 redirects to move all visitors from HTTP to HTTPS.
2. Ensure your CMS (e.g., WordPress) is correctly configured to use HTTPS.
3. Check your website for mixed content and broken links due to URLs still pointing to HTTP.
4. Update your sitemap and resubmit to Google Search Console under the HTTPS property.

Step 5: Monitor and Renew

Let’s Encrypt DV certificates expire every 90 days and are designed for automated renewal. Automation can fail, so SSL certificate monitoring with 30-day advance warnings is important even for “auto-renewing” certificates. Paid OV and EV certificates typically have one- or two-year validity periods. Set a calendar reminder well before expiry — an expired certificate is just as damaging to visitor trust as having no certificate at all.

Which SSL Certificate Do You Actually Need?

Here’s a quick decision guide:

• Blog, portfolio, or informational site: A free DV certificate via Let’s Encrypt is sufficient. Full encryption, zero cost.
• Small business, agency, or SaaS: OV is the smart choice. An OV certificate adds verified business identity to your security credentials, giving prospective clients measurable confidence before they contact you — particularly important when visitors are comparing providers and evaluating trustworthiness.
• E-commerce, banking, or healthcare: EV certificates are preferred for entities that need to process financial transactions or sensitive data. While free DV certificates usually come with no financial warranty, paid OV and EV certificates often include substantial protection ranging from $10,000 to over $1,000,000.
• Multiple subdomains: A wildcard certificate covers www, blog, shop, and all other subdomains under one certificate — far cheaper than buying separate certs for each.

SSL on Managed Hosting: What’s Handled for You

If you’re on quality managed hosting, much of the above is handled automatically. Most reputable hosts provision Let’s Encrypt DV certificates and handle renewal without you lifting a finger. Our managed WordPress hosting plans include SSL provisioning out of the box — your site launches secured from day one. If you need an OV or EV certificate for a more demanding use case, or if you’re building a more complex site and need expert configuration, our web development team can handle the full setup.

Key Takeaways

• SSL encrypts data between your server and your visitors’ browsers. Without it, that data travels in plaintext.
• Browsers actively warn users about HTTP sites — this kills trust and inflates bounce rates.
• HTTPS is a lightweight but confirmed Google ranking signal. Any valid certificate does the job; you don’t need EV for SEO benefit.
• DV is free and fast. OV adds verified business identity. EV provides maximum trust for high-transaction sites.
• After installing, always force HTTPS via redirects, fix mixed content, and set up auto-renewal monitoring.
• For wildcard needs, ensure your CA supports the coverage type — EV, for instance, is not available as a wildcard option.

Need help getting SSL configured correctly on your site — or want a hosting environment where it’s handled for you from the start? Contact us and we’ll get your site secured, properly redirected, and ready to rank.