How do you convert a website to HTTPS (SSL)?

If you want to build a secure website, using SSL/TLS and HTTPS is essential. But what do these terms actually mean — and how can you enable these security protocols to switch an existing website to HTTPS?

What is SSL/TLS?

The term SSL (short for “Secure Sockets Layer”) refers to a tech­nol­o­gy used for the en­cryp­tion and au­then­ti­ca­tion of data traffic on the internet. It secures the trans­mis­sion between browsers and web servers on websites. Es­pe­cial­ly in e-commerce, where con­fi­den­tial and sensitive data is exchanged, using an SSL cer­tifi­cate — or its successor, TLS (Transport Layer Security) — is in­dis­pens­able.

Sensitive data commonly protected by SSL/TLS en­cryp­tion includes:

• Reg­is­tra­tion data: name, address, email address, phone number
• Login data: email address and password
• Payment in­for­ma­tion: credit card number, bank details
• Form sub­mis­sions
• Uploaded documents from customers

SSL/TLS ensures that com­mu­ni­ca­tion cannot be in­ter­cept­ed or ma­nip­u­lat­ed, pre­vent­ing personal data from falling into the wrong hands.

What is HTTPS?

HTTPS (Hypertext Transfer Protocol Secure) is the protocol for secure data trans­mis­sion between browsers and web servers. In contrast, HTTP is the unsecured version, where all trans­mit­ted data can the­o­ret­i­cal­ly be in­ter­cept­ed or altered by attackers. This means that when using HTTP, users cannot be sure whether sensitive in­for­ma­tion — such as credit card details — is actually being sent to the intended recipient.

HTTPS ensures data security by en­crypt­ing in­for­ma­tion during trans­mis­sion and verifying the au­then­tic­i­ty of requests. This is achieved through the use of an SSL cer­tifi­cate.

What are the benefits of SSL/TLS or HTTPS?

• Provides data pro­tec­tion and security for customers and partners
• Reduces the risk of data theft and misuse
• HTTPS en­cryp­tion is an official Google ranking factor and a standard re­quire­ment for high-ranking websites
• Enables the use of HTTP/3 for optimal website per­for­mance
• Cer­tifi­cates are easily rec­og­niz­able to users and build trust

What’s the dif­fer­ence? Free vs. paid SSL/TLS

If you want to switch your website to SSL/TLS, as mentioned earlier, you’ll need an SSL/TLS cer­tifi­cate. Solutions like Let’s Encrypt offer free, easy-to-install al­ter­na­tives to tra­di­tion­al paid cer­tifi­cates. When enabling HTTPS or creating a secure website, you now also need to decide between free and paid SSL/TLS options. One of the main crit­i­cisms of free cer­tifi­cates is that they are in­creas­ing­ly misused by cy­ber­crim­i­nals to make phishing sites appear trust­wor­thy — giving visitors the im­pres­sion of a secure website, which is only true at first glance.

In principle, free and paid SSL/TLS cer­tifi­cates mainly differ in the following aspects:

• Validity: The most notable dif­fer­ence is the cer­tifi­cate’s validity period. Most paid SSL/TLS cer­tifi­cates are valid for 12 to 24 months, while free cer­tifi­cates usually expire after just 90 days. If you choose a free SSL/TLS cer­tifi­cate, you’ll need to renew it more fre­quent­ly — although many providers offer automatic renewal.
• Ad­min­is­tra­tion: Paid SSL/TLS cer­tifi­cates typically include man­age­ment tools and support for ad­min­is­ter­ing the cer­tifi­cate. Free cer­tifi­cates usually don’t include these services, so you’ll need to handle ad­min­is­tra­tion tasks yourself unless you purchase ad­di­tion­al services.
• Domain af­fil­i­a­tion: A free SSL/TLS cer­tifi­cate can only be issued for a single domain and is bound to it. Paid SSL/TLS options, on the other hand, can include multi-domain or wildcard cer­tifi­cates that cover multiple projects and sub­do­mains.

How to convert your website to HTTPS/SSL

When you create a secure website, you can use SSL en­cryp­tion from the start. However, con­vert­ing an existing site to HTTPS does not require too much effort.

Step 1: Acquire SSL cer­tifi­cates

An SSL cer­tifi­cate functions as an identity ver­i­fi­ca­tion for a website. The official issuing authority (CA) that provides the cer­tifi­cate verifies the identity of the website owner and vouches for the accuracy of the in­for­ma­tion. SSL cer­tifi­cates are stored on the server and are retrieved each time a visitor accesses a website secured with HTTPS. There are different types of cer­tifi­cates that vary in their level of au­then­ti­ca­tion:

• Domain Val­i­da­tion (DV) Cer­tifi­cates – free and paid
  DV cer­tifi­cates offer the lowest level of au­then­ti­ca­tion. The CA only checks whether the applicant owns the cor­re­spond­ing domain. Company in­for­ma­tion is not verified, which means there is still a residual risk with this type of cer­tifi­cate.
  Suitable for: Websites where trust and cred­i­bil­i­ty are less critical and there is no risk of phishing or fraud.

• Or­ga­ni­za­tion Val­i­da­tion (OV) Cer­tifi­cates – paid
  OV cer­tifi­cates provide a higher level of security than DV cer­tifi­cates. In addition to verifying domain ownership, the CA also checks key company in­for­ma­tion. This verified in­for­ma­tion is visible to visitors, which helps build trust. Because the ver­i­fi­ca­tion process is more extensive, OV cer­tifi­cates are more expensive than DV cer­tifi­cates but offer stronger security.
  Suitable for: Websites where trans­ac­tions take place but do not involve highly sensitive data.

• Extended Val­i­da­tion (EV) Cer­tifi­cates – paid
  EV cer­tifi­cates offer the highest and most com­pre­hen­sive level of au­then­ti­ca­tion. Compared to OV cer­tifi­cates, company in­for­ma­tion is even more thor­ough­ly verified, and these cer­tifi­cates are only issued by au­tho­rized CAs. The strict val­i­da­tion process ensures maximum security and boosts trust and cred­i­bil­i­ty, though EV cer­tifi­cates are also the most expensive.
  Suitable for: Websites that handle credit card data or other highly sensitive in­for­ma­tion.

Step 2: Install and configure the cer­tifi­cate

The next step is to install the SSL cer­tifi­cate on your server. Many hosting providers handle this process for their customers. In most cases, the cer­tifi­cate can be requested directly through the customer area, and the provider will take care of the setup. For example, IONOS customers can easily add an SSL/TLS cer­tifi­cate to their existing web hosting package through their customer account — and in many packages, it’s already included by default. The exact in­stal­la­tion process varies by provider. However, hosting providers or cer­tifi­cate issuers typically offer detailed in­stal­la­tion in­struc­tions and guides. To ensure a tech­ni­cal­ly flawless setup, pay special attention to the following points:

• correct cer­tifi­cates
• correct en­cryp­tion
• ap­pro­pri­ate server con­fig­u­ra­tion

Step 3: Respond to errors and issues

During the switch to SSL/TLS, various errors can occur that may harm your rankings or even make your website tem­porar­i­ly in­ac­ces­si­ble.

Website operators who are migrating to HTTPS should:

• Avoid expired cer­tifi­cates: An invalid or expired SSL cer­tifi­cate triggers a browser warning, which un­der­mines user trust and can deter visitors.
• Set up proper redirects: To prevent duplicate content, configure 301 redirects from HTTP to HTTPS. This ensures search engines don’t treat both versions as separate sites.
• Adjust ad accounts: Embedding un­en­crypt­ed content (images, scripts, etc.) on an HTTPS site will cause browser warnings. This is es­pe­cial­ly common with ads, which are often delivered un­en­crypt­ed. Update your ad accounts to deliver content over HTTPS.
• Switch Google Search Console and analytics tools: Since HTTP and HTTPS are con­sid­ered separate websites, you need to add and verify the HTTPS version in Google Search Console and update all analytics tools ac­cord­ing­ly.
• Update the XML sitemap: Update your sitemap with the new HTTPS URLs and resubmit it to Search Console.
• Check internal and external links: Although 301 redirects will catch outdated links, you should still update all internal links to HTTPS. Depending on your CMS, this may require manual changes. For external links, try to have important backlinks (es­pe­cial­ly from high-authority sites) updated to your HTTPS version.

Free checklist download

Below you can download a brief or detailed checklist that lists and explains the most important aspects of switching a website to HTTPS.

• HTTPS Switch Checklist (short)
• HTTPS Switch Checklist (detailed)

Step 4: Monitor cer­tifi­cate duration

To ensure your HTTPS en­cryp­tion remains active, your SSL/TLS cer­tifi­cate must not expire. Regularly check its validity period and, if possible, enable automatic renewal.

• Mon­i­tor­ing: Track the ex­pi­ra­tion date of your cer­tifi­cate. Many hosting providers offer reminder features or mon­i­tor­ing tools for this purpose.
• Automatic renewal with ACME: The ACME protocol (Automatic Cer­tifi­cate Man­age­ment En­vi­ron­ment) enables automatic cer­tifi­cate renewal (e.g., for Let’s Encrypt cer­tifi­cates), helping prevent downtime and browser warnings.
• Use provider in­te­gra­tion: In many web hosting packages, automatic cer­tifi­cate renewal is already enabled by default. Check this setting in your hosting provider’s customer account.

How to check a site for a valid cer­tifi­cate

When visiting a website encrypted with a valid cer­tifi­cate, you can recognize it by the URL:

https://www.example.com

The “s” in the protocol part of the URL stands for “secure” and indicates that the page is protected by an SSL/TLS cer­tifi­cate. Depending on the type of cer­tifi­cate and the browser used, there may also be ad­di­tion­al visual in­di­ca­tors of secure en­cryp­tion:

With tools like the free SSL check from IONOS, you can verify in just one click whether your current cer­tifi­cate is correctly installed and pro­tect­ing your website from attacks.

Increased trust through secure company websites

In addition to the technical benefits of SSL/TLS en­cryp­tion, the resulting increased user trust in a company’s website — and thus in the company itself — is a key reason to create a secure website. Jeff Barto, Trust Strate­gist at Symantec, high­lights the im­por­tance of web trust and the rising ex­pec­ta­tions of users when it comes to online security.

In this context, he offers busi­ness­es three specific rec­om­men­da­tions to meet growing user ex­pec­ta­tions regarding website security:

• Integrate trust seals into the website: Trust seals signal that a website is reliable. They can certify data security, secure trans­ac­tions, or confirm that the website is free from malware.
• Implement an SSL cer­tifi­cate with a high security level: Cer­tifi­cates with higher val­i­da­tion levels provide visible in­di­ca­tors of secure en­cryp­tion directly in the browser bar, boosting user trust.
• “Always on SSL”: The SSL cer­tifi­cate should be active on all subpages of a domain — not just on the login page or checkout. This ensures con­sis­tent pro­tec­tion for users through­out their entire visit.