Germany reached the semi-finals in the previous World Cup before being knocked out by eventual winners Spain, but Muller is confident that Joachim Low's side has vastly improved since that disappointment.
"We are much better than we were then, it would be ridiculous to claim otherwise," the Bayern Munich forward told reporters.
"We did not have the quality we have now. We were not able to develop our game from the back. We had to stand deep and wait for the counter.
"Now we are much better: Our World Cup is far more sovereign than in 2010."
Germany meet France in the last eight at the Maracana on Friday.