His Persian and Hindi grammars were a marked advance upon the work of any English predecessor, and are still in use today. After being educated at Bedford School in England, Platts returned to India and, between 1858 and 1859, worked as mathematics master at Benares College and in charge of Saugor School in the Central Provinces. In 1861 he was appointed mathematical professor and headmaster of Benares College.
In 1864, Platts became assistant inspector of schools, second circle, Northwest Provinces and, in 1868, he became officiating inspector of schools, northern circle, Central Provinces.
He retired in March 1872, owing to ill-health. Platts then returned to England, and settling in Ealing, occupying himself by teaching Hindi and Persian, having mastered both languages.
He matriculated from Balliol College, Oxford in February 1881 and, in June 1881, became Master of Arts honoris causa. In March 1901, he received the degree of Master of Arts by decree.
He died suddenly in London on 21 September 1904, and was buried at Wolvercote Cemetery near Oxford.
They had one son.