The translation service is available for personal and non-commercial use (see terms of use for more details).

Credits: The service runs systems trained by:
Martin Popel
CUBBITT models, en<->cs, en<->fr, en<->pl as desribed in
Popel, M., Tomkova, M., Tomek, J. et al. Transforming machine translation: a deep learning system reaches news translation quality comparable to human professionals. Nat Commun 11, 4381 (2020).

As of Jan 19 2022, the en<->cs translation uses the upgraded CUBBITT document-level models. The advanced mode (and the API) still offers the old sentence-level models.
Shantipriya Parida
en->hi model
Dušan Variš
en<->ru, en<->de models