Both the models feature true HEPA filters - read my article on HEPA filters here
Mi has a Smart app control and works with Google assistant and Amazon Alexa while Philips purifier requires to be switched on/off manually.
Mi gives effective area coverage of 484 sq ft with CADR of 380m3h while Philips recommended room area is 226-333 sq ft.with CADR of 270 m3/hour
Mi has 3 stage air filteration contrary to Philips air purifer providing 4 stage filteration process
Philips air purifier has been tested to remove H1N1 virus and has been allergy tested by ECARF.
Warranty- MI 3 provides 1 year warranty and Philips provides 2+3 years extended warranty
So, these were the major differences between the Top 2 budget air purifiers available in India.