Can I create website translations on subdomains or folders without losing my current English rankings?

Question

I have a running website of with some hundreds of thousands of pages already indexed, let's say example.com

Website needs to be translated to some other languages with the purpose of getting more indexed and get more traffic.

If I create example.com (default, for English), es.example.com, de.example.com... The already indexed pages will remain and the other ones will be added, right?

In the other hand, if I redo all the link structure of my page creating

example.com/en/user
example.com/en/settings
example.com/es/user
example.com/es/settings
example.com/de/user
example.com/de/settings

I will lose all the indexed pages (or at least will need to be reindexed) and it takes way more effort from my point of view. Current indexation example that could be lost with change:

example.com/user
example.com/settings

Which is the best solution regarding SEO and indexation?

PS: I already read other questions like this one and understand the benefits/issues of both solutions, the difference here is that mine is a running website with some thousands of visits per day that can't be lost.

EDIT

I also read this and understand everything, but still don't know for not losing my current indexation

Answer 1

To keep your current rankings don't move the current content. For new content create subfolder.

Assume your site looks now like:

• example.com/page-one,
• /page-two etc.

Assume it is in english.

Then, if you want to translate your content into German, create a subfolder /de/ and double your site structure into it, like

• /de/page-one,
• /de/page-two.

Your English pages located in the root directory don't change their placement - ergo, they will keep their rankings. But the new folder will begin to rank after it will be visited by crawler and properly indexed.

If you would create the both language versions from scratch, you would create two language folders: en and de, but now, to keep rankings, let the existing pages on their places.

Don't forget to bind both language versions to each other with hreflang. Each page should contain them. I.e.: for page-one

<link rel="alternate" href="http://example.com/page-one" hreflang="en" />
<link rel="alternate" href="http://example.com/de/page-one" hreflang="de" />

Answer 2

You can change the URLs of your current English content without losing rankings as long as you use 301 redirects and don't change the domain name.

You could use folders if you redirect /page.html -> /en/page.html. Googlebot generally updates the URLs for currently indexed content when permanent redirects are used without changing rankings.

I would recommend subdomains because you can move the hosting of the translated content at some point if you find you need to. With folders, everything has to be hosted in the same location. It often makes sense for site speed to move your translated website closer to the people who are using it.