Which kind of humidifier is better out of cool mist one or warm mist one? i got allergies wife has nose bleeds on dry weather which kind would you buy

Either or both.: There is better or worse machine here. Choice is based on purpose, room size, noise level acceptability, ease of operation and price. Larger rooms may be better served with cool or room temperature misters. More personal spacers can benefit from warm misters. There are some models that offer both features.

Cool: Humidifiers never mist, but rely on a fan pushing air through a wick to saturate the air with water. Misters are vaporizers & do so with steam (cheap unsafe ones) or room temperature tuning fork technology. Misters often wet the room with due like coating. Humidifiers are good to replace moisture lost in a heated house. Targeting a humidity of 35-45% is best for general health.