Best Flat Irons
We tried several of the most popular hair straighteners—including Dyson, GHD, and Hot Tools models—and sent them to our lab for testing to find out if these often-pricey items live up to the hype
By Laura Murphy
A flat iron is one of the most versatile tools in your hair care arsenal. A good straightener can not only create sleek, glossy tresses but also be used for beach waves, straightening bangs, and smoothing out frizz. But like all hot tools, flat irons pack a lot of heat and have the potential to damage hair. That’s why it’s so important to find the right tool for your hair type.
How We Evaluated Flat Irons
In this Outside the Labs evaluation, three reviewers with different hair types tried out five top straighteners at a range of prices to discover which one is worth the investment. Our evaluators:
Alexis Priester, social media program manager at CR, has thick, curly hair that’s quick to frizz. When it’s straightened it falls just above the middle of her back, and when it’s curly it’s just below her shoulders.
Tara Claesagens, clerical assistant for CR’s Innovation Lab, has medium, shoulder-length hair that hasn’t ever touched hair dye.
Laura Murphy (that’s me!). I have fine, highlighted hair that has seen some damage. It is cut in layers, the longest of which reach the middle of my back, while the shortest are chin-length.
Despite our differences, we’re all looking for the same thing: A straightener that can give us a sleek style without snagging or burning our hair. We also want a straightener that’s easy and safe to use, as well as precise in its temperature.
We tried each of the straighteners at least once on freshly washed hair, and then used them a few more times for touch-ups over the course of a couple of days. Alexis used Verb Ghost Prep Heat Protectant, and I used Amika Brooklyn Bombshell Blowout spray. Tara, a brave soul, did not use any heat protectant at all. In addition to trying out the straighteners at home, we partnered with Consumer Reports’ labs to do some analytical testing of each straightener. CR testers measured how long it took for each straightener to heat up, how close it was to the temperature it claimed to have reached, and how well each model maintained its final temperature.
The results surprised us. It turns out, you might not need the fanciest straightener on the market to get the results you desire. Read on to discover which tool is right for you.
The biggest drawback of the GHD Platinum+ Styler - 1” Flat Iron is that it has only one setting: 365° F. GHD claims that this temperature is optimized and safer for all hair types. All three evaluators loved the results this flat iron delivered—and the results in the lab were promising, too.
It took about 21 seconds for the iron to heat up, and our labs measured the temperature as just slightly above the set point. It was the fastest of all the straighteners to stabilize, and the temperature remained constant afterward. The swivel cord and pivoting plates made the straightener easy to handle, and it comes with a silicone holder for storage.
The On button is on the interior of one of the arms of the flat iron, which helped keep us from bumping it while styling. The styling process was pretty smooth—Tara and I didn’t have any snags as we pulled the iron through our hair. Alexis, who has curly hair, found that she needed to do hers in smaller sections to get a good glide going. Similarly, Tara and I only needed one to two passes to get our desired style, while Alexis needed two to three. Once finished, we were all impressed with the results.
“My hair looked excellent, better than the Dyson, actually,” Alexis says. “It was so shiny and sleek and looked really healthy. No frizz on an extremely humid day.”
Still, having only one temperature setting remains a major drawback. While I appreciate GHD’s one-button user-friendly approach, with my fine, mostly straight-laying hair, I suspect I could have achieved my desired style at a lower temperature setting.
The Dyson Corrale straightener has three heat settings, ranging from 330° F to 410° F. The gift edition we bought comes with a case, heat-resistant travel pouch, paddle brush, and detangling comb, plus a charging stand and a charging cable, both of which attach magnetically to the flat iron. It features a press-and-hold power button; a screen that shows battery level, temperature setting, and charging status; flexible plates that “mold shape and gather hair” for greater control while styling; and a flight-safety setting that isolates the heaters from the battery so that you can safely carry the straightener on an airplane.
Our labs measured the actual high temperature at about 30 degrees below 410° F—the largest variation out of all the flat irons we tested. And at 97 seconds, it was also the slowest to reach 350° F. But once heated, the temperature remained stable.
It took me a minute to figure out how to take the straightener out of flight safety mode, but once I did it was easy to operate. Dyson’s directions are clear, and the company’s website offers a number of tutorials. The iron makes noises when it turns on, when it reaches the desired temperature, and when it’s idle.
The cordless styling was a total game-changer—none of the other straighteners we tried had this option. Tara and I were able to achieve our desired style within one to two passes. Alexis had more trouble because she didn’t charge the Dyson completely before use and it kept running out of battery, which resulted in a distracted 60-minute total styling time.
Tara says the flexible plates helped keep the hair in place: “They don’t just flatten wavy hair but actually straighten all around.”
All of us got soft and shiny results from the Corrale, but we also felt some dryness in texture.
Cost remains the biggest obstacle for our testers. “This straightener is excellent, but it’s still pricey,” Alexis says. “If you can afford the splurge, it’s great. But you can probably get something almost as good for half the price. This feels like something you buy if you unexpectedly got a little extra on your tax return.”
Dyson’s flight safety mode is nice, but there’s no way I would travel with a $500 appliance in my suitcase. I wouldn’t want to risk losing it with my luggage, plugging it into a foreign outlet with unpredictable voltage levels, or leaving it behind in my hotel room. When it comes to jet-setting, the Conair Double Ceramic 1-inch Flat Iron is a far better option: it’s light, it’s easy to use, and it’s cheap enough that if you were to lose it, it wouldn’t ruin your vacation.
The Double Ceramic has five settings—ranging from 265° F to 410° F. Our labs measured the actual high temperature at just slightly above 410° F, and it took about 30 seconds for the iron to reach 350° F. Once set, the temperature swung about 6 degrees from its set point, meaning the heating isn’t as constant as the higher-end models we tested. It features a swivel cord, digital controls, and pivoting plates. The power button locks to prevent the iron from accidentally being turned off during use.
The Double Ceramic is a little clunky to use. The touchpad panel on the handle sometimes takes a couple of taps to activate, and its placement on the handle makes it easy to accidentally bump while styling, which can result in inadvertently changing your settings. It took all of us up to three to four passes to achieve our desired style, and the extra time with the heat resulted in hair that was a little on the dry side.
But the iron is small, light, and easy to manipulate, which makes it a great choice for travel. “The 1-inch width allowed me to get pretty close to my roots,” Alexis says.
She also added that she liked the large, bright display of the control panel and liked that it indicated which temperatures work best for certain hair types. “I could see this being a great flat iron for a beginner or a teenager just learning to style their own hair,” she says.
I can’t help but notice that nearly every stylist I’ve encountered uses Hot Tools, so I was curious to find out if that perfect post-salon look could be achieved just by using the same tools as the hairdresser. Turns out (surprise, surprise) technique does count for something, but we were still impressed with how the Hot Tools hair straightener performed—especially given that it’s very reasonably priced.
In our labs, the Hot Tools straightener heated up fast, though its actual temperature sat just under 350° F. Of all the straighteners, it had the biggest temperature swings—ranging up to 20 degrees from its set point during testing. Like the Conair, its plates are slightly longer at 4¼ inches, which is nice for people with longer hair. It has a long cord and is of average weight, but don’t leave it plugged in—auto shutoff doesn’t kick in until 2 hours of disuse.
As a styling tool, we found the Hot Tools straightener easy to use. I especially liked the many heat settings, with the lowest being at 205° F. Only the CHI offers a lower setting, 180° F. The rest of the straighteners start at 265° F or higher. The tool is easy to handle and offers snag-free styling.
I was able to achieve my desired style without my hair feeling parched afterward, which is a big win. The straightener itself is simple—it’s not fancy or flashy like the Dyson and GHD models, but it gets the job done. If you’re looking for a deal, Hot Tools is the way to go—maybe that’s why so many stylists use it.
The CHI was the gold standard straightener of the early aughts. I was a college student at the time, and owning a CHI meant fielding lots of requests to borrow the straightener before a big night out. I was lucky enough to have a roommate who was happy to allow me to use hers. She was also the first person to introduce me to the necessity of using a good heat protectant (thanks, Paige!).
But it has been almost two decades, and the salad days of straighteners are over. CHI now has a lot of competition, and I was eager to see how this formerly beloved brand performed against new entries into the market. Unfortunately, the results from our labs revealed average marks across the board. The actual high temperature was 390° F, compared with the advertised temperature of 410° F. It took 46 seconds to heat up, and our sensors showed moderate temperature swings of about 10 degrees when stable. At 15 ounces, it’s in the middle of the pack when it comes to weight, and the cord is a little short, measuring 78 inches.
The straightener comes with a thermal mat with elastic bands attached so the mat can be wrapped around the tool. This is something I like because it takes about 20 minutes for the tool to cool. I don’t have the bathroom counter space to leave anything out, so I’m constantly throwing still-hot hair tools back into my front hall closet, where they share space with scarves and other items that could get singed. So far, I haven’t started any fires, but the possibility is never far from my mind.
The straightener itself is straightforward—maybe a little too straightforward. “There are literally no bells and whistles to this one,” Alexis wrote in her review. “The indicator light goes from flashing to solid when it’s ready. It would be fairly easy to pick up when hot.”
The way the temperatures are noted on the dial makes it difficult to select a precise heat setting. Tara guessed that she had set it somewhere between 300° F and 360° F, while Alexis estimated somewhere between 360° F and 410° F. That’s a pretty wide range, and when you have fine, damaged hair like I do, 50 degrees can make a big difference.
The placement of the dial also made it easy to knock while styling. And the thicker plates on this straightener made it difficult to get all the way down to the root. This makes it a less ideal choice for people with bangs and curlier hair.
That said, the CHI did deliver the soft, shiny results that I remember from my college days.
What to Look For in a Straightener
When it comes to hot tools, it’s critical to choose one that offers a range of temperature settings.
According to Michele Green, a board-certified cosmetic dermatologist, “Hot hair tools should have distinct settings in terms of what temperature the tool reaches and how hot or cool the tool can get, so the user has control over how much heat is delivered to the hair and can adjust based on hair type.”
Beyond that, Gregorio Ruggeri, a master colorist and board-certified trichologist based in New York City, counsels shoppers to “dig deep and have a look at your favorite stylists’ tools of choice. Don’t be fooled by overpriced hot tools; even the most expensive can create serious damage.”
Materials
Straighteners work by clamping onto the hair and pulling it through two heated plates. The material of those plates determines how evenly the heat is spread across the plates, how quickly they heat, and how hot they get. Today, you can find straighteners made with ceramic plates, titanium plates, metal and glass plates, and plates containing tourmaline, as well as plates made of some combination of these materials.
Green recommends that those with fine, thin, or damaged hair use straighteners with ceramic plates. These plates tend to take longer to heat up but are more gentle on the hair. That said, she cautions that these tools may take more passes to achieve desired results.
Titanium, meanwhile, heats up more quickly. According to Green, titanium’s heat conductivity may make it more suitable for those with coarse or thick hair that is more difficult to smooth and straighten.
Many straighteners have plates composed of more than one material.
“Newer styling tools may include tourmaline, a naturally occurring element that emits negatively charged ions to eliminate static and reduce frizz,” Green says. “Tourmaline is often incorporated into titanium styling tools that have the benefit of heating up quickly.”
Finally, straighteners with metal or glass plates tend to be cheaper, but buyer beware: Green warns that these materials don’t distribute heat as evenly, which can cause hot spots and burn the hair.
How to Avoid Damage When Styling
Hair is most fragile when it’s wet, Green says, so to protect your hair while styling, step 1 is to make sure that it’s completely dry before you start. She recommends that people with curly hair blow dry their hair to ensure hair is completely dry. Blow drying can also smooth out the strands a little, which can minimize how much time you need to spend straightening. Those with wavy, straight, or fine hair, however, can get away with air drying.
It’s critical to apply a heat protectant before styling. “Heat protectants work by acting as a barrier between the hair and the tool, and slowing down the conduction of heat,” Green says.
For a protective barrier that doesn’t cause buildup in the hair, Green suggests looking for a protectant composed of water-soluble silicones. Some protectants may contain beneficial oils that not only protect hair but also nourish it. However, it’s important that the oils are lightweight and have a high smoke point, Green says.
“Denser oils with low smoke points will sizzle the hair when the tool is applied, leading to significant damage,” she says. “Argan oil, avocado oil, and grapeseed oil can be beneficial heat protectants.”
Finally, choose the right temperature for your hair. Green says 325° F to 375° F is ideal but adds that “the temperature should be adjusted depending on hair type.” Those with fine or damaged hair should opt for the lower end of the range, and those with thick or coarse hair should opt for the higher end. For those who have been burned before, it may be tempting to go even lower, but Green cautions against this. “Be careful using settings below 300° F, as you may be inclined to do multiple passes for the desired results, which can cause more damage in the process.”
Lastly, don’t overdo it. Ruggeri advises using hot tools as little as possible, “once to twice a week for irons, tongs, or barrel brushes. Blow dry every third day if you can, and try to use a medium setting.”
To combat moisture loss from all the heat, he suggests using a hair mask every week.
“Listen to your stylist,” Ruggeri says. “If they say there is damage from excessive use of hot tools, listen to what they suggest” for alleviating that damage.
How to Get Pin-Straight Hair
When it comes to achieving that sleek, pin-straight, early-aughts look, I turned to Ted Gibson, an influencer, hairdresser, and celebrity stylist with a client list that includes stars such as Jessica Chastain, Lupita Nyong’o, Angelina Jolie, and many more.
Gibson straightens 1.5-inch sections at a time. “If you have finer hair, you can take a little larger section,” he says. “If you have coarser hair, I might even take a half-inch or inch section instead of the inch and a half.”
After straightening, he recommends using a flexible-hold hairspray and then brushing the hair. “This gives more shine,” he says, “and helps to give control to the freshly straightened hair.” He also likes to add a little shine oil for added glossiness.
The most important thing, Gibson stresses, is to give yourself enough time to achieve your desired style. “Make sure your hair is 100 percent dry, use the right product for your hair type, and never try to do it all in one piece.”
This product evaluation is part of Consumer Reports’ Outside the Labs reviews program, which is separate from our laboratory testing and ratings. Our Outside the Labs reviews are performed at home and in other native settings by individuals, including our journalists, with specialized subject matter experience or familiarity and are designed to offer another important perspective for consumers as they shop. While the products or services mentioned in this article might not currently be in CR’s ratings, they could eventually be tested in our laboratories and rated according to an objective, scientific protocol.
Like all CR evaluations of products and services, our Outside the Labs reviews are independent and free from advertising. If you’d like to learn more about the criteria for our lab testing, please go to CR’s Research & Testing page.
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