There are a number of differences between Hajj and Umrah however, the major differences are listed below:
Hajj is the fifth pillar of Islam and is mandatory for everyone who is physically and financially able to perform it once in a lifetime. Umrah is not a pillar if Islam and is a recommended act of worship; it is not obligatory.
Hajj must be performed in the prescribed time period of the months of Hajj whereby the major rites are completed in the first two weeks of Dhul-Hijjah. However, Umrah can be performed any time of the year.
Umrah involves only the rites of Tawaf (around the Ka’bah) and Sa’i (between Safa and Marwa) with Ihram. However, Hajj involves a lot more whereby the pilgrim has to stay in Mina, perform the rites of Wuquf (standing) in the plains of ‘Arafat, stay in Muzdalifah, and pelt the stone pillars, as well as sacrifice in some cases. Umrah, however, does not involve any of these.