What is French word for one level up?

There isn't one specific French word that directly translates to "one level up."

However, depending on the context, here are some options:

General:

* Un niveau supérieur: This literally means "a higher level."

* Au niveau supérieur: This means "on the next level" or "to the next level."

* Un cran au-dessus: This is a more informal way to say "one step up" or "a notch higher."

Specific contexts:

* In a game: "Niveau supérieur" or "Niveau suivant" (next level) would be the most common.

* In a hierarchy: "Un poste supérieur" (a higher position) or "Une promotion" (a promotion) might be appropriate.

Ultimately, the best French phrase to use will depend on the specific situation.