Yes, fairer is the normal comparative degree of the English adjective fair.
It is used thus...
It was a fairer system of justice.
or He was much fairer than his father...
However, sometimes the Frenchified form "more fair" seems better, as in "he was more fair than his father.".
The comparative and superlative are fairer and fairest.
"She is fair, and fairer than that word, of wondrous virtues."
Couldn't Be Fairer was created in 1984.
The duration of Couldn't Be Fairer is 3000.0 seconds.
fairer
Stanley B. Fairer has written: 'Europe? In a tent??'
International Resources for Fairer Trade was created in 1995.
fairer
To fair means "to smooth or even out unevenness." Fairer is the comparative form of the adjective fair.
terror, seer
The correct spelling is "fairer".
fairer, fairest