The Spaniard finished second behind Sebastian Vettel in the drivers' championship last season and was voted Driver of the Year by Formula 1 team principals.
When asked if he felt there was room to improve on last year's showing, Alonso told Autosport: "I think always you can improve and I am ready to do so.
"Last year was the best year of my career and I was very happy with the performance, but I think this year will be better.
"We have a better starting point, and I have learned from some mistakes of last year. You can improve always as a driver in terms of tyre management, and in terms of preparation approach for the grand prix.
"I have prepared better; I am better than last year."
The 2013 season begins with the Australian Grand Prix in Melbourne on March 17.