The company claims that in blind tests comparing DeepL Translator to similar services, expert translators preferred DeepL’s results by a factor of 3:1.
DeepL Translations Are Private
DeepL states that all texts are deleted immediately after the translation has been completed. The translations transmitted to their server are fully encrypted and cannot be accessed by third parties. All operations comply with European Union Data Protection laws.
Update: Apparently, the free version of DeepL may not respect your privacy. The texts of free users are used to train and improve the neural networks and translation algorithms.