Hair straightener A flat iron’s test procedure
Over 50 products from over 20 manufacturers were evaluated in our penultimate flat iron test, and 18 more were evaluated in our most recent test. Our Climatology Chamber tests each iron’s ability to keep straight hair on swatches of frizzy hair. To do this, we measure the width and thickness of hair straightener after 24 hour exposure to a controlled amount of relative humidity – shown below is a comparison of straighteners that maintain their straightness after 24 hours (left) versus straighteners that do not.
In addition, we consider the weight and size of each iron, the ease of use, the satisfaction of users, the ability to impart shine and smooth hair, and durability, safety, and effectiveness. The results of our latest test came in at 4,914 heat data points, 972 survey questions and 108 swatch expansion measurements.
Are professionals using a hair straightener or curling irons?
When shopping for flat irons, it can be confusing to know which is the best. Some claim to prevent damage while others claim to provide a healthy shine, so when it comes to choosing, it can be confusing.
Titanium flat irons are preferred by professionals due to their durability. A celebrity-favorite hair salon’s stylist. Titanium gets hot really fast, which is why it’s preferred by stylists. The even heat distribution of titanium results in smooth, silky hair, says stylist Sabrina Porsche. Moroccanoil’s artistic director, Kevin Hughes, agrees that titanium is ideal for flat iron plates. It heats up quickly and evenly, so you are going over the same strands of hair less often and getting better results.
Ceramics or tourmaline are excellent choices. It does not get extremely hot when these plates are used on thin/fine hair,” Porsche says. In addition to providing faster results, ceramic flat irons are safer for your hair because they use less heat.In any case, our Beauty Lab pros have found great flat irons come in many shapes and sizes, from ceramic to titanium and beyond. As a result, don’t get too caught up in the material claims, and instead focus on other important aspects like adjustable heat settings, cord length, and budget.”.
Hair straightener: what to look for when shopping
The heating element, a good digital thermometer, the quality of the plates, and the length of the cord are all factors that contribute to making a great flat iron. The best flat irons are ones that sit comfortably in your hands, have an even heat distribution and a choice of temperatures so that you don’t damage your hair. Here are some other things to keep in mind:
hair straightener Temperature
✔️ You can select a temperature that suits your hair straightener type and needs with a flat iron that has multiple heat settings. For all hair types, a temperature range would be helpful on flat irons, according to Hughes. There’s no need to turn on the iron all the way when most irons go up to 430oF! Since temperatures above 450oF can destroy hair’s protein content, irreparable damage can result if you always start at a lower temperature and increase as needed, we recommend starting at a lower temperature. The best temperature ranges for different textures are not scientifically defined, but our pros averaged all recommendations from manufacturers for fine, medium and thick, coarse hair. Fine hair should stay between 240°F and 330°F, medium to normal hair at 330°F and thick, coarse hair at 390°F.
Plates size on the hair straightener
✔️ Hughes recommends on the hair straightener plates are one inch wide and one inch long. These narrower plates also make it easier to get closer to the root of the hair and they make it easier to do detailed styling (like curling, bending, or waving). In some cases, if your hair is very long and you are just looking to press it straight, a 1.5-inch or 2-inch wide plate will make the task much faster.
hair straightener cord
✔️ The length of the cord might not be an issue if you’re styling your hair in a bathroom or close to an outlet, but if you don’t have an outlet near your mirror, you might want to get a longer cable (or “professional” cable). The average cord length in our study was 8.1 feet — the longer the cord, the more convenient and range you will have. Hughes also recommends the cord to swivel so you can move easily while using it.
Auto-shutoff
✔️ It is easy for people to forget to turn off an iron when they are running late, so auto-shutoff ensures you some peace of mind when you’re running late, says Hughes. We tested that auto-off varied from five minutes to two hours, which is handy when you don’t quite remember if the tool was turned off, but you still need to shut it off and unplug it after use to make sure it is completely off.
Lava Ceramic Hairstyling Iron

GH’s expert hair straightener evaluators awarded this speed-heating, power-smoothing flat iron a rare perfect score, making it our top pick. During tests, it was rated as top at straightening hair and keeping it frizz-free all day long since it heated up to 96% of the maximum temperature in 60 seconds. In addition to gliding smoothly through hair and being easy to use, testers commented that “noticeable shine” appeared immediately after only one pass.
Hair Straightener Pros
- Style that dazzles
- Performance that meets expectations
- There are many options for the interface
Hair Straightener Cons
- Life of batteries is short
- Issues related to vulnerability
- An expensive product
1” Flat Iron with Anti-Static Technology

This hair straightener has over 36,00 Amazon reviews and an average rating of 4.6, and people are absolutely raving about it, and it has an astonishing number of great features for an under-hair tool, even though we haven’t tested it in the Lab. You can adjust the temperature up to 410oF according to your hair type by using floating ceramic plates coated with titanium for even heating and a silky smooth glide through the hair.
Hair Straightener Pros
- Low-cost
- An advanced product
Hair Straightener Cons
- Other picks may be more durable
Glider Ceramic Flat Iron

There are over 58,000 five-star reviews on Amazon for this flat iron, which is undoubtedly the best flat iron money can buy (and !). In one pass, it is able to smooth hair and cut down on styling time. It scored the lowest for ease of use and satisfaction in our Beauty Lab tests, with testers saying it had difficulty adjusting the heat dial, as well as taking the longest of all irons to heat up. Additionally, we found that it remained unstraight for a long period of time.
Hair Straightener Pros
- One of Amazon’s most popular reviews
Hair Straightener Cons
- Beauty Lab scores are low
Salon Straightener Copper Smooth Flat Iron

In spite of the thickest hair and the longest lengths, Revlon’s 1-inch wide tool will leave your hair straight for a long time. In our tests, its range of temperature was 180°F to 455°F, while at 455°F it had the highest temperature.”It made the process quicker,” a pro noted after testing a plate using 9 inches (“but not too long!” testers said!). In our technical test, it maintained hair straightness exceptionally well, but it fell short of maintaining straight, shiny, frizz-free hair all day, so make sure you use an anti-frizz serum to prevent hair frizz!.
Hair Straightener Pros
- Fast and easy hair smoothing with long plates
- Adaptable to many different types of hair thanks to its wide temperature range
Hair Straightener Cons
- As soon as the temperature is reached, there is no audible tone
- Compared to the norm, the cord is shorter
Pro 1″ Pearl Ceramic Flat Iron

Smooth, stay-in-place strands come from this lightweight Remington hair dryer. Our most recent test showed the tool to have the lightest weight of all the winners (0 grams).As far as maintaining sleekness, it tied for first place at 77 pounds. Another evaluator noted that for difficult-to-manage frizzy hair, it was the perfect iron, achieving effective straightening in one pass. The device heated up to 93% of its claimed temperature in 60 seconds, which is faster than the advertised 15 seconds.
Hair Straighteners Pros
- Sleekness that endures the test of time receives the best scores
- Moves easily due to its light weight
Hair Straighteners Cons
- Cord length that is shorter than average
Lucea ID 1” Smart Flat Iron

You can adjust the styling temperature automatically using personal information such as hair length and texture. Our Lab pros say that people often use settings that are too hot instead of the right temperature. With nine temperature settings, this iron is perfect for everyone, so you will never scorch even the finest hair. Top scores were earned for lasting shine, with testers praising the product’s effortless glide through hair that did not pull or tug.The T3 press gives me perfect straight and shiny results every time I do a silk press.” says Porsche.A 60-minute auto shut-off feature ensures safety, as well as instructions for retouching and manual setup.
Hair straightener Pros
- The settings you need to suit your hair type are personalized
- Hair that is silky, shiny, and smooth gets the best scores
Hair straightener Cons
- Power and adjustability buttons on the touch screen were difficult to operate according to testers
- Heats up slowly
Platinum+ Professional Performance Styler

Straightening and curling hair is easy with this flat iron, thanks to its rounded edges and 1-inch plate. Even as you curl your hair, the plates won’t snag or break. Testing in the lab showed the flat iron reached 99% of its claimed temperature within 30 seconds, which is the fastest of all flat irons. This device maintains a consistent, steady temperature of 365° to prevent hair from being damaged by excessive heat, and it is designed to provide even heat across the entire plate, so that even styling is possible. We interviewed several celebrity stylists for this article, including Mane Addicts stylist Sabrina Porsche. She recommends GHD irons to anyone with natural hair who wants to use an iron that will not harm their hair.
Hair straightener Pros
- Protects hair against damage by maintaining 365o
- Curling hair is made easier with rounded edges
Hair straightener Cons
- Some hair types may not be able to adjust the temperature
Nano Ultra-Thin Straightening Iron

For anti-frizz studies, this iron is used as our test standard in the Beauty Lab. Consumer testers report that it glides easily through hair without tugging. It’s safe to say this flat iron from BaBylissPRO is obsessed with people, since it has over 10,000 5-star reviews on Amazon. Having such a thin titanium iron and plates that go all the way to the clamp, the titanium iron can nip frizz at the root, making it the perfect iron for hair that has stubborn frizz or that is super-curly or wavy. It claims to get rid of frizz in one pass without additional styling time, according to one Amazon reviewer with “very curly hair.”.
Hair Straightener Pros
- Frizzy hair is smoothed by extending the plates to the edge of the iron
- Glides over hair smoothly
Hair Straightener Cons
- A switch that shuts off automatically is not available
- Other irons heat up faster than this one
Polished Perfection Straightening Brush 2.0

Using this brush, you won’t have to learn styling skills to create smoother strands, and the hair won’t look crunchy or too straight at the roots. This isn’t the straightener that gets your hair as pin-straight as it might with a traditional straightener. However, we recommend it whenever your hair is misbehaving but doesn’t need to be straightened. In half the time it took one of our editors to straighten her curly hair, it saved her a lot of time.
Hair Straightener Pros
- The roots retain volume
Hair Straightener Cons
- The ability to style is limited
Corrale Hair Straightener

With one 70-minute charge, one Dyson flat iron can style cordlessly for more than 30 minutes. This makes it ideal for travel (or bathrooms with inconvenient outlets). Unlike traditional flat irons with solid surfaces, Dyson’s plates are flexible, so hair won’t get squished flat, giving hair extra volume and a style that “retains volume but stays straight and has body.”.Experts found that while it was heavy and bulky, it didn’t appear to be a problem.”In terms of performance, the Dyson excelled: It reached 95% of its claimed temperature in 60 seconds while retaining a steady plate temperature for 15 minutes. The outside surface temperature remained cool to the touch throughout. It pulled and snagged hair more than other irons in our Lab tests after 24 hours of humidity exposure.
Hair Straighteners Pros
- Both cordless and corded options are available
- Getting voluminous hair while still keeping it sleek is possible with flexing plates
Hair Straightener Cons
- The profile is bulky and heavy
- Setting range is narrow