Correct spelling, explanation: this word is a present participle/gerund of the verb commit. The correct version consists of the double -m and the double -t. It comes from Latin committere and the etymology signalizes this kind of spelling. It’s worth mentioning that when we create a present participle of a verb and there is a single vowel before the last consonant in it, we need to double that consonant. Committing is the only correct spelling and comiting is incorrect.

Definition of committing:
verb, doing, performing, perpetrating
I recently listened to a podcast about a person who kept committing murders.
It is only human to commit an error.

Incorrect spelling, explanation: the right form committing is a derivative of the verb commit. It must accord with its root, so this is the reason to double the first consonant – -m. The reason to double the second consonant – -t – is that in the English language we have a rule based on which when there is a single vowel before the last consonant in a word, we need to double that consonant. Comiting is not the correct version.

Incorrect spelling

Incorrect spelling