Pte Williams was a "loving and caring son", his family said.
A British soldier who died while trying to retrieve the body of an Afghan comrade has been named.
Private Jason Williams, 23, of Worcester, died after an explosion on Saturday east of Gereshk in Helmand province, the MoD said.
The soldier, from 2nd Battalion The Mercian Regiment, was described as a "loving and caring son and brother".
Lt Col Simon Banton, commanding officer of 2nd Battalion The Mercian Regiment, hailed Pte Williams's bravery.
The death, which occurred on Saturday, takes the UK death toll in Afghanistan since 2001 to 196.
On the day of his death, Pte Williams' platoon was securing an area following an attack in which three Afghan soldiers died.
His family issued a statement which said: "Jason was a loving and caring son and brother.
"The Army gave him a sense of purpose and enthusiasm for life which stretched beyond the boundaries of his work. We are so proud of Jason and we will miss him every day."
Lt Col Simon Banton, commanding officer of 2nd Battalion The Mercian Regiment, said no mission or task was too great for Pte Williams.
He added: "On the day he died Jason was taking part in an action which adhered to every soldier's oldest code: leave no man behind.
"His brave determination and commitment to his brothers in arms ensured that the Afghan warrior's family are able to pay their proper respects to their own fallen son."
Five UK soldiers have been killed in Afghanistan so far in August, following a record death toll of 22 in July.
Troops are now involved in the second stage of Operation Panther's Claw, which the MoD says is focused on holding ground won from the Taliban in recent weeks.