[lokl]

If you don't absolutely need the integration/CLI, I recommend FineReader (Standard edition). You can specify that the document can contain text from a set of languages (e.g., German and English) and it will auto-detect appropriately. If you need automation (of import, processing, export), this can be done with FineReader Server (formerly known as Recognition Server), but the pricing is quite high for personal use. FineReader Corporate edition has limited automation -- if sufficient for your needs, the pricing might be much more reasonable. I have used the Standard edition and Recognition Server extensively, but have not used the Corporate edition. If you really want a cloud service, you can make your own with their Cloud SDK or use their FineReader Online, but I also have no experience with these.

As for accuracy, the details of your documents and scanning can matter, but, for normal personal usage, it should be very high.

[gingerlime]

I've heard good things about FineReader, but I'm using Linux and it doesn't look like it's available, also to automate the scanning workflow (and I can't really justify spending that much of it).

[ocrcustomserver]

There's ABBYY FineReader Engine CLI for Linux: https://www.ocr4linux.com/