His Persian and Urdu grammars were a marked advance upon the work of any English predecessor, and are still in use today.
Platts then returned to England, and settling in Ealing, occupying himself by teaching Urdu, Hindi and Persian, having mastered the languages.
He matriculated from Balliol College, Oxford in February 1881 and, in June 1881, became Master of Arts honoris causa.
He died suddenly in London on 21 September 1904, and was buried at Wolvercote Cemetery near Oxford.
Platts married twice: first, in 1856, in Lahore, Pakistan, to Alice Jane Kenyon, by whom he had three sons and four daughters; and second, in 1876, to Mary Elizabeth Hayes of Melbourne, Australia.