Giroud, who passed Thierry Henry to become France's all-time top goal scorer earlier in the tournament, said Les Bleus had had to be at their best to beat England.
Coach Didier Deschamps said France beat a good England side with their "heart and guts" on Saturday to move into the World Cup semi-finals and keep alive their hopes of back-to-back titles.
An Olivier Giroud header 12 minutes from time kept alive French hopes of becoming the first team in 60 years to retain the World Cup with a 2-1 win over England.
"It's fabulous, it was a big game," said Deschamps.
"We played a superb England team who are strong technically and physically.
"It's brilliant for the players to be in the last four again. In these moments you kind of wish time could stop for a while.
"But tonight we're going to enjoy it. We got a bit lucky although we gave away two penalties. We kept our lead with our hearts and our guts."
England captain Harry Kane equalised with a penalty in the 54th minute but sent a second penalty half an hour later over the bar.
Giroud, who passed Thierry Henry to become France's all-time top goalscorer earlier in the tournament, said Les Bleus had had to be at their best to beat England.
"This goal tonight, the 53rd, is even better (than equalling Henry). Just before I had a chance that I should have hit harder and scored," he said.
"I thought I might get another chance and when it came to me it was an unbelievable feeling to score.
"You need to keep believing," he added. "(Antoine Griezmann) gave me a super ball, it's so good for the team, it's awesome.
"We knew the potential of this young England team. They have everything but we played a solid game, we tried to hurt them on the break. We went for it with all our mental strength."
France will be heavy favourites when they play Morocco - the first African team ever to reach the semis after their 1-0 win over Portugal -- on Wednesday looking to reach a third World Cup final after winning the title in 1998 and 2018.
"We will prepare for the next game thoroughly. Morocco deserve praise," said Deschamps.
"Maybe they were not expected here (in the last four), but they conceded only one goal and then, seeing them here is not a surprise at all."
