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

If you want to create a secure website, switching from HTTP to HTTPS is essential. But what exactly does this mean — and how can you convert your website to HTTPS quickly and safely?

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. Es­pe­cially in e-commerce, where con­fid­en­tial and sensitive data is exchanged, using an SSL cer­ti­fic­ate — or its successor, TLS (Transport Layer Security) — is in­dis­pens­able when you switch your website to HTTPS.

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.

When you convert your site from HTTP to HTTPS, data is encrypted during trans­mis­sion and the au­then­ti­city of your website is verified through an SSL cer­ti­fic­ate.

What are the benefits of switching to 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 re­cog­nis­able to users and build trust

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

If you want to migrate your website to HTTPS, 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, you 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 switch your website to SSL/HTTPS, you can use en­cryp­tion from the start — but con­vert­ing an existing site to HTTPS is also straight­for­ward.

Step 1: Acquire an SSL cer­ti­fic­ate

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 au­thor­ised 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 migration from HTTP to HTTPS, various errors can occur that may harm your rankings or even make your website tem­por­ar­ily in­ac­cess­ible.

Website operators who are switching 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 recognise 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 change to HTTPS. 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.