10 Best Hair Straighteners, According to Our Beauty Lab's Tests

Speed-heating and power-smoothing, this CHI earned a rare perfect score with GH’s expert evaluators and was by far our top-tested flat iron. In tests, it warmed up to 96% of max temp in 60 seconds, although our pros wish there was an audible tone to indicate when it reaches temperature. Still, it ranked best in almost all categories, including fully straightening hair and keeping it sleek and frizz-free all day. It also got perfect marks from testers for gliding smoothly through hair and being easy to use, with all commenting on the "noticeable shine" in just one pass.

TESTER SAYS: "I really like how fast I was able to style my hair," said one tester, with another saying, "I would buy this product in a heartbeat."

This under $40 stunner wowed us in Lab tests. It's a great value, but keep in mind that it took longer to heat up than other models the Lab evaluated (more than two minutes), so be sure to power it up well before you start styling. It has a super long cord, which is rare to find in this price bracket—the longer the cord, the easier it can be to style hair.

TESTER SAYS: Testers loved its size, rated it highly for being comfortable to hold, and praised its controls too: "Good temperature setting options, lightweight, easy to hold and use," a tester said.

Maintaining a constant temperature of 365°F, this ghd straightener is able to quickly straighten hair within one to two passes. Beauty Lab Director Sabina Wizemann found that the iron kept her hair straight and shiny for a full day.

EXPERT SAYS: "I've never gotten so many compliments on my hair as I did after using this flat iron," Wizemann said. "Generally, when I used this iron, my hair still kept its straight shape the next day. What I especially liked was that it straightened my hair quickly, usually in one stroke, but it didn't flatten it severely; instead, my hair still maintained volume and emphasized the curved hair cut of my bob. I also appreciated that it doesn’t require fiddling with temperature adjustments; with one setting, all the guesswork is eliminated, and my hair looked and felt sleek and healthy."

A GH Beauty Award-winner, this innovative plate-free straightener uses high-pressure airflow to straighten hair as it dries, which the brand claims is less damaging to hair. The airflow is projected downwards at a 45-degree angle to mimic a super-smooth blowout and create the tension needed for a pin-straight finish in one step, even on curly hair (Jessica Teich, former GH Director of Editorial Commerce and Product Reviews, tried it on type 3 curls, below, and can confirm). It also has both wet and dry styling capabilities and features a setting that allows you to blow dry your roots without clamping down on strands.

It doesn't come without drawbacks, though: First, it's extremely expensive at $500. It's also a bit limited in its versatility since it only straightens hair and doesn't allow for much volume in the resulting style. Teich found that it's a bit bulky to use and store. Still, if you religiously straighten your hair and are concerned about excessive heat damage, we think it could be a worthy investment.

TESTER SAYS: "This product completely transformed my damp hair into fully dry and straightened hair," said one tester. Since it operates at a much lower temperature than traditional flat irons, a tester also said, "I was not concerned about burning my hair, face or neck." The resulting style, testers agreed, was noticeably shiny, smooth to the touch, sleek, and styled. "After styling, my hair stayed straight and frizz-free all day," a tester said.

A standout in Lab tests, this top-performing iron maintained a consistent, steady temperature of 365º to protect hair from excessive heat damage and its technology ensures even heat across the entire plate, which means easier styling and more consistent results. It got a perfect score among testers for being comfortable to hold, but the lack of adjustable temperature may be a turn-off for some (all of our testers noted they wished they could adjust the temperature), plus it lacks a temperature display. A Lab test found that the flat iron heats up fast, reaching 99% of its claimed temperature in just 30 seconds. As with most innovative tools on the market, you get what you pay for—and this flat iron is extremely pricey at over $270. It's an investment, but one that could be healthier for your hair in the long run.

TESTER SAYS: Testers loved how it made their hair feel: "smooth, shiny, and healthy without flyaways or frizz, just a perfectly straight look," although in our Lab tests, it had below average score for maintaining straightness when exposed to humidity for 24 hours. Still, it's a favorite of GH editors and several celebrity stylists we interviewed for this article. Mane Addicts stylist Sabrina Porsche says, "I recommend ghd irons for anyone who has natural hair and wants to use the best iron that won't damage your hair with heat."

Teich uses this iron regularly, and loves how it glides through her curly, thick hair like butter, making quick work of smoothing out kinks and frizz. Plus, the rounded plates make it easy to bend, wave, and even curl hair.

Boasting the widest temperature range of the flat irons evaluated, this titanium straightener has settings spanning from 200ºF to 450ºF, which makes it a Swiss Army knife of stylers: it suits a wide range of styling needs and hair types. Though, it does not have a lock feature for storage.

TESTERS SAY: Testers loved how comfortable it was to use, praising its soft-touch surface and comfortable grip. "The finger grip on the top is excellent and I liked how fast the flat iron straightened my hair," one tester said. It's on the pricier side, but one tester expressed they were "extremely satisfied with the way my hair looked afterwards," with another marveling at how "smooth" their hair felt. It also got a perfect score among testers for not burning their face, scalp, or neck, even for one who said that's been "an issue I've had with other flat irons," making it a solid choice for those who aren't confident using a heat tool quite yet.

With wider-than-average plates at 1 3/8 inches, we love this flat iron for making quick work of smoothing out longer hair. Testers called it "the perfect size," saying the width of the plates made it easy "to do a lot of styles." It was also rated highly for not pulling or snagging on hair and got a perfect score among testers for being easy to open and close, although some wished the plates closed more tightly. This pick is well-priced at under $100, but our Lab tests showed that the iron only heats up to 410ºF while on the 450ºF setting, so keep in mind that you may need to tinker with the temperature settings as you style to find the right level for your hair.

TESTER SAYS: One tester said, "my hair is very fine and dry, but I was really impressed with how smooth and shiny this flat iron made my hair."

Lightweight and bargain-priced, this Remington delivers smooth strands that stay in place. The tool was the lightest-weight of the winners in our most recent test (0.77 pounds!) and tied for best at maintaining sleekness. In Lab tests, it heated up to 93% of its claimed temperature in 60 seconds, which is speedy but not as fast as the 15 seconds claimed. Keep in mind it does have a narrow temperature range of 300-450°F, so it might not be suitable for thinner or fragile hair types, and the cord is shorter than average which can make styling cumbersome.

TESTER SAYS: "One pass for effective straightening that lasted," an evaluator said, with another adding hair "felt soft and looked straight with this iron," perfect for even tough-to-manage frizzy hair.

This iron is our Beauty Lab standard: We use it for various evaluations such as anti-frizz studies. It glides through hair without tugging and is easy to use according to consumer testers, though it does take a bit longer to heat up than other irons. Plus, with over 11,000 five-star reviews on Amazon, it's safe to say people are obsessed with this flat iron from BaBylissPRO. Because the titanium iron is so thin and the plates go all the way to the edge of the clamp, it's able to nab frizz right at the root of the hair, making this iron perfect for stubborn frizz or super-curly and natural hair. Since there's no auto shut-off with this iron, you'll have to remember to unplug it after use for peace of mind.

AMAZON REVIEWER SAYS: One Amazon reviewer who says she has "very, very curly hair," claims that this flat iron cuts her styling time in half and gets rid of frizz in one pass.

Perfect for travel (or inconveniently placed outlets in the bathroom), this Dyson flat iron can be used cord-free: The brand claims one 70-minute charge grants 30 minutes of cordless styling.

From the operational standpoint, the Dyson excelled: It heated up to 95% of its claimed temperature in 60 seconds and maintained a steady plate temperature for 15 minutes, while the outside surface temperature stays cool to the touch. However, in Lab tests, hair struggled to maintain straightness after 24-hour humidity exposure, and our experts found it pulled and snagged hair more than other irons during styling.

TESTERS SAY: Unlike traditional flat irons that have a solid surface, the Dyson's plates are flexible so hair doesn't get squished flat which "left [hair] a bit voluminous like a blowout" and a style that testers said "retained volume," yet "stayed straight and kept its body." It's heavy and bulky, but experts found that “it didn’t seem to matter during use.”