Do I really need a true HEPA air purifier?

For most household needs — allergens, pet dander, dust, pollen, smoke — a HEPA-grade filter is the standard recommendation. Specialist-community discussion on r/AirPurifiers notes that some popular consumer brands have had to walk back HEPA labeling on certain models, so it's worth checking that the specific model you're buying carries either an independent HEPA test or an AHAM Verifide CADR rating before relying on the marketing.