The invention provides a heat transfer composition comprising (i) from about 45 to about 75% by weight 2,3,3,3-tetrafluoropropene (R-1234yf); and (ii) from about 25 to about 55% by weight 1,1,1,2-tetrafluoroethane (R-134a). A heat transfer composition comprising, optionally consisting essentially of, (i) from about 20 to about 90% by weight R-1234yf; (ii) from about 10 to about 60% by weight R-134a; and (iii) from about 1 to about 20% by weight R-32 is also provided.