Professional, automatic book translations seem to be possible now, new tools are developed all the time and this blog post is about a promising one
Deepl versus Google Translate
Virtually everyone knows Google Translate, and Deepl works in a similar way. They are supposed to produce better quality translations than Google Translate and after having tried it, I do agree.
Deepl’s paid version comes with an additional advantage because it deletes translated documents, once the job is done. Google Translate does not guarantee anything like that and we can’t be sure how they are using our texts. With Deepl’s free version, however, you have to be as careful as with Google Translate.
Something else to bear in mind
For the time being, I would recommend being cautious with automatic translations because they are still producing lots of mistakes and the trickiest ones are those that SEEM right but are not. Errors may even be easier overlooked than with manual translations.
Change will eventually happen
So far, I am not willing to pay for automatic translation, but this might change in future, because it is improving all the time. The more data is fed into a system, the better the result.
In general, non-fiction will work better with automatic translation than fiction, which tends to be more complex.
By the way: none of the professional book translators I have talked to was currently willing to use Deepl.
I believe there will gradually be more and more authors, who translate their books via Deepl or similar tools and ask translators to do the final edit, which will then be faster and cheaper, although I am sure, a thorough final edit will always be necessary.
There are other options
For those who want to publish internationally and cannot or do not want to spend a lot of money, I would not yet recommend the translation route.
In many countries, people are willing and able to read books in English, and Amazon offers affordable ads in Germany now, the most encouraging market for self-publishers after English-speaking countries.
One self-published American author even told me she had sold more ENGLISH-LANGUAGE books in Germany than anywhere else.