Do I need a diffuser attachment?

If you have wavy, curly, or coily hair, yes a diffuser is essential. It disperses the airflow over a wider area and reduces direct force, which prevents curls from being blown out of their natural pattern. Without a diffuser, concentrated airflow creates frizz and disrupts curl formation. If you have straight hair and primarily blow dry for smoothness or volume, a concentrator nozzle is more useful. Several dryers on our list include both attachments.