The Bio Ionic worked well on all of our testers’ hair, but it’s best on drier hair with a medium thickness. We spritzed testers’ hair with some keratin smoothing treatment, but the Bio Ionic did a lot of the heavy lifting to make our hair feel softer. The tool gets hot, but not too hot to grip, and it excels at creating the silky volume you want without making your hair pin-straight and flat. One tester put it perfectly: “[The Bio Ionic] is the Rumplestiltskin of hair straighteners. It’s turning straw into gold.”
EDITOR’S CHOICE: As the only hair straightener we reviewed featuring Keratin-infused ceramic plates, the LumaBella Keratin Duel Touch Hair Straightener is our top choice for the healthy, shiny hair you’ve always dreamed wanted! With a unique, floating plate design and smart heat sensor, this hair straightener is ideal for a variety of hair types and reduces breakage and splitting by up to 50%.
At $230, the Bio Ionic is pricier than any of our top picks. But you get what you pay for. You can truly do with your hair whatever you desire — straight or curled — in one pass. And, if you’re worried about it breaking a few years after purchase, the Bio Ionic comes with a five-year warranty. By investing in a better-quality tool up front, you won’t have to replace your flat iron every couple of years. Plus, the Bio Ionic goes on sale every now and then, so it’s worth keeping your eye out for deals.
Negative ions have been a longtime fan favorite in the hair care industry, and it is no surprise that this same technology would appear in our top picks for the best hair straightener. Negative ions have been found to reduce static and frizz while locking in moisture, and the same goes for your hair when you use the CHI Air Expert Classic Tourmaline Ceramic Flat Iron!
With well over 25,000 reviews, the HSI Professional Ceramic Tourmaline Ionic Flat Iron is one of the best straightening irons you can get, but because of its thin build and rounded plates, you can also use it to curl your hair. It’s got solid ceramic plates to reduce damage, evenly heat hair, and promote shine, and if you’re a traveler, it’s got a dual voltage that can be used anywhere in the world.
Once you have purchased your new hair straightener and mastered the multitude of ways you can put it to good use, the only thing left to do is take care of it, so it lasts for years to come! Just like any luxury beauty tool, you will want to care for your hair straightener to extend its longevity and prevent corrosion (which can actually leak into your flowing locks…yuck!). Our top tips for caring for and cleaning your new hair straightener include:
Unlike the Bio Ionic’s handy digital temperature control, the Chi Air uses a small dial on the side of the tool that’s harder to read. The dial’s placement makes it not only more difficult to get an accurate reading, but also more prone to being hit by your hand and switching to a new temperature. That being said, most of our testers didn’t mind this minor inconvenience since they don’t expect to change the tool’s temperature often.
The ½ inch plates allow the BaBylissPro Mini to get close to the scalp, so it will straighten hair from root to tip. It's lightweight and compact at 6 inches long, so it will fit easily in a purse or carry-on bag with no hassle. It comes with a heat resistant travel pouch for storage so you can pack up and go at a moment's notice before or after straightening your hair.
We usually roll our eyes at oil-infused heat tools — but you can actually watch this oil being sucked right out of the refillable cartridge in the handle. When you press the iron closed over your strands, the oil vapor seeps through tiny holes to condition and straighten your hair. And don't worry fine-haired friends: It made our tester's hair silkier, but not like she'd dipped it in an oil vat.