What they share
Both are European classics with deep royal heritage and centuries of use. Both are three syllables, both wear well at every age, and both have a small family of warm short forms to choose from (Lottie, Charlie; Ellie, Nora, Nell).
Pick Charlotte if…
Pick Charlotte if you want the crisper, more polished classic. Charlotte is the feminine form of Charles and means 'free woman'. It carries a polished, continental feel and shortens beautifully to Lottie or Charlie depending on your preference.
Pick Eleanor if…
Pick Eleanor if you want the softer, more literary option. Eleanor is of Old French origin and has been worn by queens, writers, and statesmen. Nora, Nell, and Ellie each feel distinct as short forms, which gives Eleanor unusual flexibility.
Charlotte is the slightly more formal of the two; Eleanor the slightly more romantic. Both will wear beautifully in every setting for the whole of a life. If the nicknames matter to you, consider which short form you want to use every day and work backwards from there.