First, make sure the diffuser is compatible with your current hair dryer. Measure the nozzle’s diameter and check the diffuser’s packaging or product description for compatible sizes. If it says “universal,” chances are it will fit. Most blow dryer nozzles are around 1.5 to 2.5 inches, so anything in that range should work just fine.
Then, keep in mind the results you’re aiming for, whether it’s added volume, enhanced definition, or faster drying. Think: longer prongs for lifted roots, closely spaced prongs for defined curls, more vents for quick drying, fewer vents for frizz control, smaller bowls for tighter curls, and larger bowls for long, thick hair. If you travel often, a collapsible diffuser could be your best bet.
Is it better to air-dry curly hair or use a diffuser?
If you’re looking for the best results, diffusing is the way to go—even a few minutes can make a big difference. “Diffusing your curly or wavy hair even just for a few minutes before air drying will help set your style and reduce frizz,” says Joseph. While air drying is quick and convenient, it can sometimes lead to frizz or uneven texture. Diffusing enhances curl definition, boosts volume, and helps lock in that just-left-the-salon softness, giving your curls a more polished, long-lasting finish.
Is hot or cold air better for diffusing curly hair?
Both hot and cool air have their benefits when it comes to diffusing curls. Hot air helps speed up the drying process and set your curl pattern, but it can pose a risk of heat damage if not used carefully. “Heat from diffusing won’t typically damage your curls,” says Joseph, “but I always keep the dryer temperature on low and use the fan speed to increase drying time instead of turning up the heat.” Using a low heat setting with increased airflow offers a safer way to dry curls efficiently without sacrificing definition. For the best results, finish with cool air once your curls are mostly dry to help lock in moisture and reduce frizz.
Meet the experts
- Evan Joseph, curl expert and founder of Evan Joseph Salon in San Diego, CA
- Cathy Sripramong, curly expert and founder of Tangles Salon in Pasadena, CA
How we test and review products
We always enlist a range of testers for any review, but hair-care products and tools are another story. While some can be used across different hair textures, lengths, curl patterns, thicknesses, colors (natural and unnatural), and concerns, many are created with specific consumers and their needs in mind. When reviewing tools, we also take into account testers’ experience levels. For instance, an innovative new blow-dryer may feature industry-leading technology, but if the only people who find it intuitive to use are professional hairstylists, we have to consider this when determining whether it is worthy of a recommendation.