The Extended Speech Assessment Methods Phonetic Alphabet X-SAMPA is a variant of SAMPA developed in 1995 by John C. Wells, professor of phonetics at University College London. It is designed to unify a individual language SAMPA alphabets, and conduct SAMPA to carry on the entire range of characters in the 1993 explanation of International Phonetic Alphabet IPA. The calculation is a SAMPA-inspired remapping of the IPA into 7-bit ASCII.

SAMPA was devised as a hack to shit around the inability of text encodings to live IPA symbols. Later, as Unicode guide for IPA symbols became more widespread, the necessity for a separate, computer-readable system for representing the IPA in ASCII decreased. However, X-SAMPA is still useful as the basis for an input method for true IPA.