HTTPS certificate explained: everything you need to know
An HTTPS certificate is essential for every modern website. Whether you run a blog, operate an online store, or have a company website, without an HTTPS certificate you lose visitors and risk security problems. In this in-depth article we explain everything about the HTTPS certificate: what it is, how it works, and why you should install it today.
What exactly is an HTTPS certificate?
An HTTPS certificate, technically an SSL/TLS certificate, ensures that the connection between your website and your visitor's browser is encrypted. The "S" in HTTPS stands for "Secure". When you install an HTTPS certificate on your server, your URL changes from http:// to https://, and a padlock appears in the browser's address bar.
The certificate contains important information:
- The domain name the certificate was issued for
- The owner of the certificate (with OV and EV)
- The certificate authority that issued it
- The validity period of the certificate
- The public key for the encryption
How does an HTTPS certificate work technically?
The process behind an HTTPS certificate is based on asymmetric encryption and the so-called TLS handshake. Below we explain it step by step:
- The browser requests a secure connection: when a visitor opens your website over https://, the browser sends a request to your server
- The server sends the certificate: your web server responds with the HTTPS certificate and the public key
- The browser verifies the certificate: the browser checks whether the certificate is valid, not expired, and issued by a trusted authority
- A session key is created: the browser and server jointly create a unique session key for this connection
- All data is encrypted: from now on all communication is encrypted with the session key
This entire process takes only milliseconds and is invisible to the visitor.
Why do you need an HTTPS certificate?
There are several compelling reasons to install an HTTPS certificate on your website:
1. Protection of data
Without an HTTPS certificate, data is sent as plain text. This means anyone on the same network, think of public Wi-Fi, can intercept the data. With HTTPS, all communication is encrypted and unreadable to third parties.
2. Visitor trust
Modern browsers show a clear warning when a website does not use HTTPS. Chrome displays "Not secure" in the address bar, which scares visitors away. With a valid HTTPS certificate, visitors see a trusted padlock.
3. SEO benefits
Google has confirmed that HTTPS is a positive ranking factor. Websites with an HTTPS certificate have an edge in the search results over unsecured sites.
4. Legal requirements
The GDPR requires you to take appropriate technical measures to protect personal data. An HTTPS certificate is seen as a basic requirement for meeting this.
Types of HTTPS certificates: which are there?
There are various types of HTTPS certificates, each with their own characteristics and use cases:
| Type | Validation | Lead time | Ideal for | Cost |
|---|---|---|---|---|
| Domain Validation (DV) | Domain only | Minutes | Personal sites, blogs | Free to €50/year |
| Organization Validation (OV) | Domain + organization | 1-3 days | Company websites | €50 to €200/year |
| Extended Validation (EV) | Extended verification | 3-7 days | Online stores, financial | €150 to €500/year |
| Wildcard | Domain + subdomains | Variable | Sites with subdomains | €80 to €400/year |
| Multi-Domain (SAN) | Multiple domains | Variable | Multiple websites | €100 to €600/year |
Installing an HTTPS certificate: step by step
Installing an HTTPS certificate differs per hosting environment, but the general process is as follows:
Step 1: Choose the right certificate type
Determine which type of HTTPS certificate you need based on your website and budget. For most websites a DV certificate is sufficient.
Step 2: Generate a Certificate Signing Request (CSR)
A CSR is a file you create on your server. It contains information about your domain and organization, plus your public key. Your hosting provider often offers a tool for this in the control panel.
Step 3: Submit the CSR to a certificate authority
Send the CSR to the certificate authority (CA) of your choice. With a DV certificate you only need to prove that you manage the domain, for example through a DNS record or email verification.
Step 4: Install the certificate
After approval you receive the HTTPS certificate. Install it on your web server. With many web hosting providers this is a matter of uploading the certificate through the control panel.
Step 5: Force HTTPS
Set up a redirect from HTTP to HTTPS, so that all visitors automatically visit the secure version of your website. You do this through your .htaccess file or server configuration.
Step 6: Test your installation
Use tools such as the SSL Labs Server Test to check whether your HTTPS certificate is installed correctly and your configuration is secure.
Common problems with an HTTPS certificate
During the installation and use of an HTTPS certificate you can run into various problems:
- Mixed content: your page still loads some files (images, scripts) over HTTP. Fix this by changing all URLs to HTTPS or using relative paths
- Expired certificate: if your certificate expires, visitors see a big warning. Set up automatic renewal
- Wrong domain name: the certificate must exactly match your domain name (including or excluding www)
- Chain errors: sometimes intermediate certificates are missing. Install the full certificate chain
- Redirect loops: incorrect redirect configuration can cause an infinite loop
Free HTTPS certificate with Let's Encrypt
Let's Encrypt is a free, automated certificate authority backed by major tech companies. It offers DV certificates that are automatically renewed every 90 days.
The benefits of Let's Encrypt:
- Completely free: no cost at all
- Automatic: renewal and installation are fully automated
- Widely supported: most hosting providers support Let's Encrypt
- Just as secure: the same 256-bit encryption as paid certificates
With many SSL certificate providers and hosting parties, Let's Encrypt is included by default. Check whether your hosting offers this.
HTTPS certificate and performance: does your site get slower?
A frequently heard objection is that an HTTPS certificate makes your website slower because of the extra encryption. In practice this effect is negligible thanks to modern optimizations:
- TLS 1.3: the newest version of the protocol minimizes the number of handshakes
- HTTP/2: this faster protocol is only available over HTTPS, so your site actually gets faster
- Session resumption: repeat connections are faster because session data is reused
- OCSP stapling: reduces the time needed for certificate validation
In most cases you notice no speed difference, or your website even gets faster thanks to HTTP/2.
HTTPS certificate checklist for your website
Use this checklist to verify that your HTTPS certificate is set up correctly:
| Check | Status | Action if there is a problem |
|---|---|---|
| HTTPS active on all pages | Required | Set up a server redirect |
| No mixed content | Required | Change HTTP references to HTTPS |
| Certificate not expired | Required | Set up automatic renewal |
| Correct domain on the certificate | Required | Request a new certificate |
| TLS 1.2 or higher | Recommended | Update the server configuration |
| HSTS header set | Recommended | Add a Strict-Transport-Security header |
| HTTP/2 active | Recommended | Enable it in the server configuration |
The future of the HTTPS certificate
The use of HTTPS is growing steadily. By now, more than 95% of all web traffic is loaded over HTTPS. The trend is clear: HTTPS is becoming the standard and HTTP is increasingly being blocked by browsers.
A few developments to keep an eye on:
- Shorter validity period: there are proposals to shorten the maximum validity to 90 days
- Automation: more and more processes around certificate management are being automated
- Certificate Transparency: all issued certificates are publicly logged for more transparency
- Post-quantum cryptography: preparation for the arrival of quantum computers that can break current encryption
An HTTPS certificate is not a luxury but a necessity for every website. It protects your visitors, improves your SEO, increases trust, and helps you meet legal requirements. With free options such as Let's Encrypt, there is no excuse left to leave your website unsecured.
Want to know more about SSL certificates and which type suits your website best? Then take a look at our extensive SSL certificate page for a complete overview of all the possibilities.
HTTPS certificate explained: technical operation
To understand why an HTTPS certificate is so important, you need to know how it works technically. The underlying technology protects millions of websites worldwide.
The TLS handshake
When a visitor opens your website, a TLS handshake takes place between the browser and the server. The browser requests the SSL/TLS certificate, checks its validity with the Certificate Authority, and negotiates the encryption protocol. This entire process takes only milliseconds but ensures that all data sent afterwards is encrypted. Modern browsers use TLS 1.3, which is faster and more secure than older versions.
Symmetric vs asymmetric encryption
An HTTPS certificate uses both types of encryption. Asymmetric encryption (with a public and private key) is used during the handshake to securely exchange a session key. After that, the connection switches to symmetric encryption (with the shared session key) for the actual data communication. This combines the security of asymmetric encryption with the speed of symmetric encryption.
HTTPS certificate and SEO: the impact
Google uses HTTPS as a ranking signal. Having an HTTPS certificate is therefore not only important for security, but also for your visibility in search engines.
Direct and indirect SEO benefits
The direct benefit is that Google treats HTTPS as a positive ranking signal. Websites with HTTPS get a small ranking boost over HTTP websites. The indirect benefits are at least as important: browsers show warnings on HTTP websites, which scares visitors away and increases your bounce rate. A high bounce rate is negative for your SEO. In addition, HTTPS is required for HTTP/2, which makes your website significantly faster. Read more about how to become more findable in Google.
Migrating from HTTP to HTTPS
If your website still runs on HTTP, migrating to HTTPS is a priority. The steps are: install an SSL certificate, configure a 301 redirect from HTTP to HTTPS, update all internal links to HTTPS, update your sitemap and robots.txt, and register the new HTTPS URL in Google Search Console. A correct migration prevents temporary ranking drops. Don't forget to also check your DNS configuration after the migration.
Solving HTTPS certificate problems
Sometimes an HTTPS certificate does not work as expected. Below you will find the most common problems and their solutions.
Common SSL/TLS errors
| Error message | Cause | Solution |
|---|---|---|
| ERR_CERT_DATE_INVALID | Certificate expired | Renew the certificate at your provider |
| ERR_CERT_COMMON_NAME_INVALID | Wrong domain | Request a certificate for the correct domain |
| ERR_SSL_PROTOCOL_ERROR | Server configuration | Check the TLS version and cipher suites |
| Mixed Content | HTTP resources on an HTTPS page | Update all resources to HTTPS |
| ERR_CERT_AUTHORITY_INVALID | Untrusted CA | Use a recognized Certificate Authority |
Setting up automatic renewal
Prevent certificate problems by setting up automatic renewal. Let's Encrypt certificates expire every 90 days and must be renewed in time. Most hosting providers handle this automatically through Certbot or a similar tool. Check monthly whether the automatic renewal is working correctly. For paid certificates: set a reminder in your calendar at least 30 days before the expiry date to start the renewal process on time.
HTTPS certificate: practical implementation guide
Implementing an HTTPS certificate on your website requires a systematic approach. Start by requesting the certificate through your hosting provider or a Certificate Authority. After installation you need to update all internal links from HTTP to HTTPS. Configure a permanent 301 redirect so that HTTP traffic is automatically forwarded to HTTPS. Update your sitemap.xml and robots.txt with the new HTTPS URLs. Register your HTTPS website in Google Search Console as a new property. Check for mixed content warnings with browser developer tools and fix them. Test your SSL configuration with SSL Labs (ssllabs.com/ssltest) to verify that you achieve an A rating. A correct HTTPS implementation improves your security, SEO, and user trust all at once.
HTTPS certificate: the future
The future of the HTTPS certificate is shaped by ever stricter security standards. Browsers mark HTTP websites as insecure more and more prominently, which increases the pressure to use HTTPS. TLS 1.3 is becoming the standard with faster handshakes and better security. Certificate Transparency requires all issued certificates to be logged in public databases, which makes fraud harder. Automatic certificate issuance through the ACME protocol (such as Let's Encrypt) makes HTTPS accessible to everyone. In time, browsers may block HTTP pages entirely. Make sure your website already runs fully on HTTPS to be ready for this future.
HTTPS certificate: frequently asked questions
We answer the most frequently asked questions about the HTTPS certificate here. Is a free certificate just as secure as a paid one? Yes, the encryption is identical; the difference is in the validation and warranty. How long does the installation take? With most hosting providers it is a matter of a few clicks. Do I need to change my website after installing HTTPS? Yes, all internal links must be updated to HTTPS and you need to set up a redirect from HTTP to HTTPS. Can I turn HTTPS off again? Technically yes, but this is strongly discouraged for security and SEO reasons.
HTTPS certificate: summary
In 2026, an HTTPS certificate is no longer an option but an absolute necessity for every website. It protects your visitors, improves your SEO ranking, and builds trust. With free Let's Encrypt certificates at most hosting providers, there are no more excuses not to secure your website. Install an SSL certificate today, configure the redirect from HTTP to HTTPS, fix any mixed content problems, and register your HTTPS website in Google Search Console. A correctly configured HTTPS certificate costs you nothing but delivers better security, higher rankings, and more trust from your visitors. At Theory7 a free SSL certificate is included by default with every hosting plan.
HTTPS certificate: installation per platform
Installing an HTTPS certificate differs per hosting platform. With cPanel you go to the SSL/TLS Manager, select your domain, and install the certificate with one click. With Plesk you navigate to Websites and Domains, choose SSL/TLS Certificates, and upload or generate your certificate. With DirectAdmin you find the SSL option under Account Manager. On a VPS or dedicated server you install the certificate manually through the command line with certbot for Let's Encrypt, or by placing the certificate file in the correct Apache or Nginx configuration. After installation you test with the Qualys SSL Labs Server Test at ssllabs.com for a detailed analysis of your SSL configuration.
HTTPS certificate: solving mixed content
A common problem after activating your HTTPS certificate is mixed content: pages that load over HTTPS but still contain HTTP resources for images, scripts, or stylesheets. This results in a broken padlock in the browser. Find mixed content with the browser console (F12, Console tab), which shows HTTP resources as warnings. Fix it by updating all internal URLs to HTTPS. With WordPress you use the Better Search Replace plugin to replace all HTTP URLs in the database with HTTPS. Add a Content-Security-Policy header with upgrade-insecure-requests to automatically load any remaining HTTP resources over HTTPS.
HTTPS certificate: impact on performance
Some website administrators worry about the performance impact of an HTTPS certificate. In reality the difference is negligible: the TLS handshake adds only a few milliseconds to the first connection. With TLS 1.3 the handshake is even faster thanks to a reduced number of roundtrips. HTTP/2, which requires HTTPS, more than compensates through multiplexing, header compression, and server push. Websites with HTTPS and HTTP/2 usually load faster than HTTP/1.1 websites without encryption.
HTTPS certificate: implementation checklist
- SSL certificate obtained - through a hosting provider or Certificate Authority
- Certificate installed - configured and activated on the web server
- HTTP to HTTPS redirect - 301 redirect set up for all pages
- Mixed content fixed - all internal resources load over HTTPS
- Internal links updated - all URLs in the database changed to HTTPS
- Sitemap updated - HTTPS URLs in the XML sitemap
- Google Search Console - HTTPS property registered and sitemap submitted
- Canonical tags - pointing to the HTTPS version of each page
- SSL Labs test - score A or higher achieved
- Automatic renewal - configured and verified
With this checklist you make sure your HTTPS certificate is implemented correctly and your website is optimally secured for visitors and search engines.
An HTTPS certificate is the foundation of a safe and reliable website. With the information from this article you can choose, install, and maintain the right certificate for optimal protection of your visitors and better performance in search engines.
Sources and references
- SSL Labs, SSL Server Test by Qualys (ssllabs.com)
- ACM, Netherlands Authority for Consumers and Markets (acm.nl)
- Dutch Data Protection Authority, GDPR information (autoriteitpersoonsgegevens.nl)
