Good is subjective. Most translation software seems to send WAV files to amazon or google clouds for processing.
If you want 100% self-contained, I’ve been using ‘apertium’ from their PPA for a few years. Sometimes the translations get confused over gender stuff, but
it is sufficient to understand if you have a little knowledge of the other language and how sentence structure works.
Apertium is a text-2-text translation tool. Looks like they have many supported languages. The main limitation is that Latin letters must be used, so no Korean/Japanese/Mandarin to English.