Diacritics are those glyphs added to the Esperanto letters ĉ, ĝ, ĥ, ĵ, ŝ, ŭ, and their uppercase variant.

In Esperanto, the only letters using diacritics are ĉ, ĝ, ĥ, ĵ, ŝ, ŭ, and their uppercase variant. The difference between those letters and the equivalent without diacritics is the pronunciation.