Romaji is the representation of Japanese sounds using Latin alphabet characters. The two main systems are Hepburn (used on passports and station signs) and Kunrei-shiki (used in Japanese education).

Japanese input methods (IME) primarily use romaji input, where typing Latin characters on a keyboard converts them to hiragana. Japanese input method guides teach efficient romaji typing techniques.

For character counting, romaji characters are counted as half-width (1 character each). The same Japanese text written in romaji tends to have a higher character count than in hiragana.

Romaji is sometimes used in URLs and filenames when Japanese characters are impractical. Japanese learning books for beginners cover romaji reading and writing as a foundation.