Our verdict

We've found the On Cloudflyer to be a distinctive blend of versatility and stability. It's loved by many, including us, for its superb build quality—a signature of On shoes. This shoe also offers a flexible yet stable ride, even suitable for overpronators. However, we noticed its firm midsole might not be for everyone. While the Swiss brand's pricing leans towards the higher end as usual, the Cloudflyer is a great all-rounder for those willing to pay a premium price.

Pros

  • Well-suited for wide feet
  • Excellent for cross-training or HIIT
  • Flexible yet provides excellent stability
  • Outstanding build quality
  • A rocker that works
  • Ideal for heel strikers
  • Promotes good airflow

Cons

  • Firm cushioning
  • Probably too expensive

Audience verdict

88
Great!

Who should buy

We think that the On Cloudflyer is an excellent pick for:

  • Runners who prefer a firm midsole and want a stable shoe.
  • Individuals who value premium-quality materials and require a versatile running shoe that can manage everything from gym workouts to walks in the park.
  • Enthusiasts of the On brand looking for a reliable shoe for easy and aerobic runs.

On Cloudflyer

Who should NOT buy

If you're working with a tight budget, this shoe, priced at £170, is not a good choice. In our opinion, there are many other stability-oriented shoes on the market that may suit you best like the Saucony Tempus.

Similarly, if soft midsoles are what you're after, we suggest giving this shoe a pass. From our testing of On's lineup, we recommend choosing the Cloudmonster instead. And, if you're in search of a plush and reliable daily trainer, we suggest the Nike Pegasus 40 based on our experience.

On Cloudflyer

Breathability

When we first got our hands on the shoe, we thought its breathability might be less than ideal due to the dual-layer upper—something we've seen in other On shoes like the Cloud X.

Yet, we were in for a surprise! After testing the Cloudflyer with our smoke-pumping machine in the lab, we found much more airflow than we expected, giving the shoe a solid 4 out of 5 in this test.

Next, we took it to the light test, which clearly showed us where the air was flowing through the upper.

On Cloudflyer microscope

Even under our microscope, we didn't see any large ventilation holes or extremely thin mesh. This is why we were so surprised by the shoe's great ventilation.

On Cloudflyer mesh

Test results
Cloudflyer 4
Average 3.8
Compared to 221 running shoes
Number of shoes
1
Breathability
5

Durability

Toebox durability

The good news just keeps comin'.

Even though this may not be the most rugged upper we've put to the test, it's undoubtedly better than what you'd find on most other shoes out there. However, it's still below the amazing performance of the On Cloudswift 3 in this same test.

On Cloudflyer Toebox durability
Test results
Cloudflyer 3
Average 2.3
Compared to 155 running shoes
Number of shoes
1
Toebox durability
5

Heel padding durability

But then we switched to the heel, and the narrative flipped. It's just not built to last at all, which is a bummer. So for runners who are quick to wear out the heel area on running shoes, this one's a heads-up!

Test results
Cloudflyer 1
Average 3.2
Compared to 151 running shoes
Number of shoes
1
Heel padding durability
5

Outsole hardness

Clocking in at 83.3 HC, the outsole is slightly harder than the median, but it doesn't seem like it's enough to mess with the grip.

On Cloudflyer Outsole hardness
Test results
Cloudflyer 83.3 HC
Average 80.4 HC
We use an average of four tests. The photo shows one of those tests.
Compared to 272 running shoes
Number of shoes
54.9 HC
Outsole hardness
92.8 HC

Outsole durability

To understand its durability, we put the shoe to the ultimate test with our Dremel tool for one last time.

After this intense yet brief workout, we noted a 0.88 mm dent, which lines up with the hardness we had already measured.

On Cloudflyer Outsole durability
Test results
Cloudflyer 0.9 mm
Average 0.9 mm
Compared to 133 running shoes
Number of shoes
0.0 mm
Outsole wear
2.0 mm

Outsole thickness

With a slim 2.2mm profile, the outsole is designed to shave off extra weight.

On Cloudflyer outsole

Given its proven durability, it's unlikely that any runner will encounter issues throughout the shoe's life. However, we'd feel more secure with a 3mm-thick outsole, just as an added safety-net.

On Cloudflyer Outsole thickness
Test results
Cloudflyer 2.2 mm
Average 3.2 mm
Compared to 291 running shoes
Number of shoes
0.0 mm
Outsole thickness
6.6 mm

Weight

The Cloudflyer doesn't come across as heavy, nor does it feel exceptionally light during walks or runs. It just occupies a comfortable middle ground.

Nevertheless, we appreciate On's effort to keep it below the 10 oz benchmark, which we believe is a fantastic achievement for this shoe. It weighs only 9.90 oz (281g).

On Cloudflyer Weight
Test results
Cloudflyer 9.91 oz (281g)
Average 9.38 oz (266g)
Compared to 292 running shoes
Number of shoes
5.26 oz (149g)
Weight
12.56 oz (356g)

Cushioning

Heel stack

This shoe boasts a stack height of 30.5 mm. Combined with the unique CloudTec foam setup, it provides sufficient cushioning for most runs.

However, we found ourselves craving a tad more cushion during those longer training sessions. For those 15 or 20-milers, we suggest considering an alternative like the Nike Invincible 3.

Additionally, the Cloudflyer is also great for heel strikers because it has a noticeable rockered shape. This feature makes the transition from heel to toe smooth and easy.

On Cloudflyer Heel stack
Test results
Cloudflyer 30.5 mm
Average 33.6 mm
Compared to 291 running shoes
Number of shoes
7.6 mm
Heel stack
42.7 mm

Forefoot stack

As we move to the forefoot, we see a shift. Regrettably, there's only 20.5 mm of stack height, which isn't a lot.

While this is sufficient for easy or moderate runs, we can't recommend this shoe for midfoot or forefoot strikers who are really into high mileage.

On Cloudflyer Forefoot stack
Test results
Cloudflyer 20.5 mm
Average 24.9 mm
Compared to 291 running shoes
Number of shoes
7.6 mm
Forefoot stack
35.8 mm

Drop

The differential adds up to a 10-mm heel-to-toe drop. Yet, On claims a 7 mm drop. Why this variance?

The answer lies in our measurement approach; we adhere to the official guidelines from World Athletics, something we think On might not be doing.

This discovery might prompt you to reconsider this shoe, particularly if you were relying on a moderate drop.

On Cloudflyer Drop
Test results
Cloudflyer 10.0 mm
Average 8.7 mm
Compared to 291 running shoes
Number of shoes
-0.8 mm
Drop
16.1 mm

Insole thickness

One common and cost-effective strategy in the running shoe industry involves using an insole that's thicker than usual in order to enhance comfort, particularly with low-stack or firm midsoles.

That's the exact tactic On uses in this case with their 6-mm insole. And now, let's uncover the reason why.

On Cloudflyer Insole thickness
Test results
Cloudflyer 6.0 mm
Average 4.5 mm
Compared to 287 running shoes
Number of shoes
1.5 mm
Insole thickness
7.3 mm

Midsole softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

With a hardness level of 31.3 HA, On stays true to its tradition, offering a firm midsole in the heel area. However, this may not be the best fit for those seeking a more plush experience even when paired with a thick-and-plush insole.

On Cloudflyer Midsole softness
Test results
Cloudflyer 31.3 HA
Average 21.4 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 219 running shoes
Number of shoes
8.5 HA
Midsole softness (soft to firm)
41.5 HA

Secondary foam softness

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.

This shoe sports a double-foam configuration aimed at providing stability for heel strikers, and added comfort for forefoot strikers.

We find this approach interesting. However, with a hardness level of 28.3 HA, the forefoot foam is still bit too firm for our liking.

On Cloudflyer Midsole softness
Test results
Cloudflyer 28.3 HA
Average 25.2 HA
We use an average of four tests. The photo shows one of those tests.

Midsole softness in cold

Note: a low durometer measurement equals a soft material, whereas a high measurement means it's firm.
On Cloudflyer Midsole softness in cold

Difference in midsole softness in cold

We placed the shoe in our freezer for 20 minutes to mimic winter conditions. After this, we found the midsole hardened significantly to 40.3 HA. It's then that the Helion midsole truly starts to feel as firm as a brick.

This marks a 28.8% jump from the room-temperature reading. Although this aligns with most modern midsoles, it falls short of the top performers. And we mustn't overlook that this shoe carries a high-end price tag.

On Cloudflyer Midsole softness in cold
Test results
Cloudflyer 28.8%
Average 25.6%
Compared to 218 running shoes
Number of shoes
0%
Difference in midsole softness in cold
100%

Stability

Lateral stability test

Promoted as a stability shoe, we had high hopes for the Cloudflyer's performance in this area. And it delivered.

On Cloudflyer heel

Its wide landing platform, firm midsole, the Speedboard plate, and the plastic reinforcement around the heel counter all come together to ensure rock-solid stability.

Torsional rigidity

Torsional rigidity is another crucial factor for enhancing stability. We give it a middle-of-the-road score at 3 out of 5, signaling a well-rounded choice: it's stable but also comfy, making it suitable for gym workouts or dog-walking.

Too much stiffness would make it less ideal for cross-training or casual, everyday wear.

Test results
Cloudflyer 3
Average 3.2
Compared to 270 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

Again, as a shoe geared towards stability, it's logical that On opts for a rigid heel counter, aiming to prevent overpronation.

We value the added padding in this area to improve comfort and the fact that it's not excessively rigid. We gave it a 4 out of 5.

Test results
Cloudflyer 4
Average 2.8
Compared to 254 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width in the forefoot

Measuring at 115.0 mm, the landing platform on this On shoe provides a good balance, especially in tandem with the firm midsole. For instance, is the exact same midsole that you can find in one of the most popular stability shoes, the Hoka Gaviota 4.

On Cloudflyer Midsole width in the forefoot
Test results
Cloudflyer 115.0 mm
Average 113.6 mm
Compared to 292 running shoes
Number of shoes
100.5 mm
Midsole width in the forefoot
126.5 mm

Midsole width in the heel

However, this shoe really shines for heel strikers. With a 10-mm drop and 94.1 mm of width in the heel, it's clearly designed to complement this running style.

On Cloudflyer Midsole width in the heel
Test results
Cloudflyer 94.1 mm
Average 90.5 mm
Compared to 292 running shoes
Number of shoes
74.9 mm
Midsole width in the heel
106.6 mm

Flexibility

Stiffness

We initially thought the inclusion of the Speedboard TPU plate in the midsole would result in, at least, average stiffness for this shoe. However, our analysis offered a different story, underscoring the indispensable role of lab testing when analyzing shoes.

It only took us 13.6N of force to bend the shoe to 90 degrees. This puts it straight in the category of "one of the most flexible shoes we've ever tested".

Test results
Cloudflyer 13.6N
Average 29.3N
We use an average of four tests. The video shows one of those tests.
Compared to 274 running shoes
Number of shoes
2.2N
Stiffness
94.4N

Difference in stiffness in cold

In cold temperatures, the shoe stiffens to 20N in the same test, though it still maintains a feel of flexibility.

With only a 46.7% difference between the two measurements, this result is simply average. Again, considering the shoe's high price tag, we rightfully expect better performance from these tests.

Test results
Cloudflyer 46.7%
Average 36.3%
Compared to 274 running shoes
Number of shoes
0%
Difference in stiffness in cold
148%

Size and fit

Internal length

According to On's size charts, a US size 9 should measure 270 mm on the inside. After checking in the lab with our caliper, we found it to be 270.1 mm, which makes this shoe a textbook example of true-to-size.

On Cloudflyer Internal length
Test results
Cloudflyer 270.1 mm
Average 269.1 mm
Compared to 155 running shoes
Number of shoes
259.9 mm
Internal length
280.4 mm

Toebox width at the widest part

Let's tip our hats to On for crafting a shoe that accommodates almost every foot type.

At 102.1 mm of width, it might be a bit too roomy for those with very narrow feet—consider going half a size down if you're into this group. But for the rest of us, the Cloudflyer screams comfort, offering a spacious upper.

On Cloudflyer Toebox width at the widest part
Test results
Cloudflyer 102.1 mm
Average 98.3 mm
Compared to 292 running shoes
Number of shoes
89.5 mm
Toebox width at the widest part
109.1 mm

Toebox width at the big toe

This impressive width becomes even more apparent in the toe area. Measuring at a spacious 82.2 mm, it's one of the roomiest shoes we've ever encountered in this part.

On Cloudflyer Toebox width at the big toe
Test results
Cloudflyer 82.2 mm
Average 78.0 mm
Compared to 166 running shoes
Number of shoes
60.4 mm
Toebox width at the big toe
92.5 mm

Tongue: gusset type

When we examined the shoe, we spotted the bootie-like tongue, a feature common to many On Cloud shoes.

On Cloudflyer Tongue: gusset type
Test results
Cloudflyer Bootie

Comfort

Tongue padding

On goes above and beyond for comfort in the Cloudflyer by integrating not just one, but two plush layers of padding into the tongue.

We think that with this tongue, anyone can look forward to a smooth, comfortable run, free of any lace bite or similar discomforts.

On Cloudflyer Tongue padding
Test results
Cloudflyer 7.3 mm
Average 5.6 mm
Compared to 289 running shoes
Number of shoes
0.5 mm
Tongue padding
14.2 mm

Heel tab

While it's no surprise that this On shoe lacks a heel tab, it does feature an Ultraboost-like heel collar. This design touch made slipping into the shoe a lot easier for us.

On Cloudflyer Heel tab
Test results
Cloudflyer None

Removable insole

One big plus for this On shoe is that we can easily take out the insole. Given the spaciousness of the shoe, slipping in our own orthotics is not a problem at all.

On Cloudflyer Removable insole
Test results
Cloudflyer Yes

Misc

Reflective elements

On really nails it with their tradition of doubling their logo as a reflective element. We're totally into it—it's a win-win for everyone.

On Cloudflyer Reflective elements
Test results
Cloudflyer Yes