> In French, even though "télécharger/téléchargé" is most common and "download" is not really used, I would definitely say "je l'ai downloadé" I think the OP’s

> In French, even though "télécharger/téléchargé" is most common and "download" is not really used, I would definitely say "je l'ai downloadé" I think the OP’s problem comes from “down” being used like a standard German prefix, which does sound really awkward. Foreign verbs in French are (almost?) always used like first-group regular verbs, the only alteration is the suffix. It feels less out of place.