By the end of his presidency on January 20, 2017, Barack Obama had exercised his constitutional power to grant executive clemency—that is, "pardon, commutation of sentence, remission of fine or restitution, and reprieve"—to 1,927 individuals convicted of federal crimes. Of the acts of clemency, 1,715 were commutations (including 504 life sentences) and 212 were pardons.
Most individuals granted executive clemency by Obama had been convicted on drug charges, and had received lengthy and sometimes mandatory sentences at the height of the War on Drugs.
Obama holds the record for the largest single-day use of the clemency power, granting 330 commutations on January 19, 2017, his last full day in office.
He also has issued more commutations than the past thirteen presidents combined.
https://en.wikipedia.org/wiki/List_of_people_granted_executive_clemency_by_Barack_Obama