Simon Blevins, 26, Richard Roberts, 36, and Rich Loizou, 31, became the first UK anti-fracking protesters to be sent to prison, after climbing on lorries at Cuadrilla’s site in Lancashire.
Court of Appeal judges ruled their sentences were “manifestly excessive” and imposed conditional discharges.
The judgement was met by applause and singing from supporters in the court.
Blevins and Roberts were jailed for 16 months each and Loizou received a 15-month custodial term.
The Lord Chief Justice Lord Burnett said an “immediate custodial sentence in the case of these appellants was manifestly excessive”.
“In our judgment, the appropriate sentence which should have been imposed… was a community order with a significant requirement of unpaid work,” he said.
“But these appellants have been in prison for six weeks.
“As a result, and only for that reason, we have concluded that the appropriate sentence now is a conditional discharge for two years.”