There is no one-size-fits-all answer to this question, as the best approach for SEO will vary depending on the specific website and its goals. However, in general, subdirectories are considered to be better for SEO than subdomains when it comes to multilingual websites.
Here are some of the reasons why subdirectories are better for SEO:
Subdirectories share the domain authority of the main domain, which can help them rank higher in search results.
Subdomains, on the other hand, are considered to be separate domains, so they don’t benefit from the same level of domain authority.
Multilingual websites with subdirectories have cleaner and more concise URLs, which can make them more user-friendly and easier for search engines to index.
Subdomains, on the other hand, can have longer and more complex URLs, which can make them less user-friendly and more difficult for search engines to index.
Subdirectories are easier to manage from a technical SEO perspective. This is because they can be easily linked to the main domain, and they don’t require any additional configuration or setup.
Subdomains, on the other hand, can be more difficult to manage from a technical SEO perspective, and they may require additional configuration or setup.
The size of your website:
If your website is small, a subdomain may be a good option. However, if your website is large, a subfolder may be easy to manage. You do not need to have more than an account to manage it.
A subdomain is a separate domain that is linked to the main domain. This means that the subdomain will have its own DNS records, its own hosting, and its own SSL certificate. If you have a small website, then managing a subdomain is relatively easy. You can simply point the subdomain to the same hosting as your main domain, and you can use the same SSL certificate.
However, if you have a large website, then managing a subdomain can become more difficult. You may need to use different hosting for the subdomain, and you may need to purchase a separate SSL certificate. This can add complexity to your website management, and it can also increase your costs.
The level of connection you need:
If you need to tightly integrate your multilingual website (your subdomain) with your main website, a subdomain may be the best option. However, if you don’t need as much integration, a subfolder may be a better option.
A subdomain has a higher level of relationship than a subfolder because it is considered to be a separate website. This means that the subdomain will have its own domain authority, which can help it rank higher in search results. However, a subdomain can also be more difficult to manage and maintain than a subfolder.
A subfolder has a lower level of integration/connection than a subdomain because it is simply a directory within the main domain. This means that the subfolder will share the domain authority of the main domain, but it will not have its own domain authority. However, a subfolder is easier to manage and maintain than a subdomain.
If you have a limited budget, a subfolder may be the better option. Subdomains can be more expensive to set up and maintain.
Subdomains require separate hosting and SSL certificates. This can add to the overall cost of running a website, especially if you are hosting multiple subdomains.
Subdomains can be more difficult to manage. This is because they are separate domains, which means that they have their own DNS records and other settings. If you are not familiar with website management, this can be a challenge.
Of course, there are some cases where subdomains may be a better choice for SEO. For example, if you want to create a separate website for a specific country or region, a subdomain may be the best option. However, for most multilingual websites, subdirectories are the better choice for SEO.
Ultimately, the best way to decide whether to use a subdomain or a subfolder for your multilingual website is to consult with an SEO expert. They can help you assess your specific needs and goals and recommend the best approach for your website.