Our verdict

The Cloudrunner 2 from On marks a positive upgrade over its predecessor. We found in the lab that this mild stability shoe retains the exceptional build quality, breathability, and versatility of the first generation while introducing significant improvements like a lighter weight, increased flexibility, and a slightly-softer, bouncier Helion midsole. Despite these enhancements, the ride is still somewhat firm, and we believe the outsole requires a durability upgrade.

Pros

  • Reduced weight
  • Enhanced flexibility
  • Great for all-day wear
  • Robust stability features
  • Supports long runs
  • Improved Helion midsole
  • Premium build quality

Cons

  • Outsole durability
  • Remains somewhat firm
  • Needs to be lighter

Audience verdict

88
Great!

Who should buy

We think the Cloudrunner 2 from On is a significant upgrade. We were impressed by how it blends the heritage of the v1 with new enhancements, making it an excellent choice for:

  • Runners seeking a supportive workhorse willing to invest a little extra money when compared to similar shoes.
  • Those in need of a reliable, mid-level stability shoe that performs well across various types of runs.
  • Loyal fans of the original Cloudrunner, as this model enhances all the core features while preserving the essential DNA of its predecessor.

On Cloudrunner 2

Who should NOT buy

Although the Cloudrunner 2 is softer than the previous generation, it still offers a firm ride that may not suit fans of plusher midsoles. We believe there are better choices for those seeking a softer experience, such as the tried-and-true ASICS Gel Kayano 30, which features a plush FF Blast+ midsole.

We've also observed that the Cloudrunner 2, despite being lighter than before, still could benefit from a lighter design. If shoe weight is a concern for you, check the Hoka Arahi 7, a top choice for mild-stability footwear—it provides more cushioning, especially in the forefoot, in a lighter build.

On Cloudrunner 2 parts

Breathability

On maintains a strong reputation for the quality of its running shoes—complemented by its premium pricing—so we were really eager to analyze the upper and its airflow.

Our visually striking smoke test demonstrated that ventilation is quite effective; we rated it nearly perfect at 4/5. This confirms that the shoe will provide excellent airflow in all conditions, regardless of the temperature.

However, it's important to note that ventilation is primarily concentrated in the toebox, as On has reinforced the upper in the midfoot and heel for added structure. This design choice boosts stability and durability but does restrict airflow in these areas—a difference clearly seen when examining the upper against light.

On Cloudrunner 2 Microscope

Moving to a microscopic level, we delved into the finer details of how On crafted the upper.

On Cloudrunner 2 Micro 2

We were pleased with the results. On utilizes a multi-layered engineered mesh that not only enhances comfort but also ensures effective ventilation with sizable gaps between the threads. Afterwards, we explored the sliced upper with our hands. 

It features only minor enhancements from the first edition, which is fine since the original design was effective. The upper is comfortable and well padded, making it ideal for all-day wear. Additionally, it is crafted from 100% recycled polyester, definitely a plus.

Test results
Cloudrunner 2 4
Average 3.8
Compared to 234 running shoes
Number of shoes
1
Breathability
5

Durability

Toebox durability

During our manual assessment, we noted the shoe's mesh is composed of multiple layers—a design choice that generally boosts durability, especially compared to single-layer monomesh uppers that often fail quickly under our fierce Dremel test.

In this particular evaluation, the recycled, polyester-based mesh of the shoe held up well, earning a positive 3/5 rating.

On Cloudrunner 2 Toebox durability
Test results
Cloudrunner 2 3
Average 2.4
Compared to 168 running shoes
Number of shoes
1
Toebox durability
5

Heel padding durability

In our lab, most running shoes typically score 1 or 2 points higher in this test than in the toebox, but that was not the case with the Cloudrunner 2.

We observed the same 3/5 score here, which is slightly disappointing though not as concerning as a score of 1 or 2 would have been.

On Cloudrunner 2 Heel padding durability
Test results
Cloudrunner 2 3
Average 3.2
Compared to 164 running shoes
Number of shoes
1
Heel padding durability
5

Outsole hardness

Moving to the outsole, we noted the classic On design that's prevalent in other models like the Cloudmonster 2—a central groove paired with horizontal flex points to enhance flexibility, complemented by rubber only in high-wear areas like the forefoot and heel.

On Cloudrunner 2 outsole

The areas without rubber feature not just exposed midsole, but also rubberized EVA with a textured pattern to enhance grip.

We found slightly less rubber coverage compared to the first version, yet we believe this is still sufficient to withstand wear and tear for most runners, potentially contributing to weight reduction.

In terms of hardness, the outsole measured 85.4 HC, slightly above average, which we hope will translate to excellent durability.

On Cloudrunner 2 Outsole hardness
Test results
Cloudrunner 2 85.4 HC
Average 80.5 HC
We use an average of four tests. The photo shows one of those tests.
Compared to 285 running shoes
Number of shoes
52.1 HC
Outsole hardness
93.0 HC

Outsole durability

Unfortunately, our results did not meet expectations after measuring the indentation left by the Dremel.

We discovered a 1.1-mm indentation, which, while not terrible, was slightly more pronounced than we had hoped for in a rubber of this type. 

On Cloudrunner 2 Outsole durability
Test results
Cloudrunner 2 1.1 mm
Average 0.9 mm
Compared to 146 running shoes
Number of shoes
0.0 mm
Outsole wear
2.0 mm

Outsole thickness

But On was aware of this issue, of course, and that's why they added a bit more rubber to those pads. Instead of the typical 3 mm used in most trainers, they increased it to 3.7 mm to compensate for the rubber's lower durability and extend the shoe's mileage.

On Cloudrunner 2 Outsole thickness
Test results
Cloudrunner 2 3.7 mm
Average 3.2 mm
Compared to 304 running shoes
Number of shoes
0.0 mm
Outsole thickness
6.6 mm

Weight

A significant drawback of the first-generation Cloudrunner was its weight, which many runners felt was excessive given its moderate stack height, tipping the scales at over 10.3 oz or nearly 295g.

Happily, we discovered that On has implemented subtle but effective design tweaks to address this concern. The Cloudrunner 2 now registers just under the 10-ounce mark at 9.7 oz or 275g. While not groundbreaking, this reduction is a welcome improvement!

On Cloudrunner 2 Weight
Test results
Cloudrunner 2 9.70 oz (275g)
Average 9.38 oz (266g)
Compared to 305 running shoes
Number of shoes
5.26 oz (149g)
Weight
12.56 oz (356g)

Cushioning

Heel stack

The Cloudrunner series is a go-to shoe for everyday runs and all-around activities. As such, we expect this line to embody a standard design in many aspects such as fit and stack height.

That's why we weren't surprised to measure the heel at 33.6 mm, a figure that perfectly aligns with moderately-stacked running shoes. This makes sense especially considering On has already established a strong presence in the maximalist segment of the market, and doesn't need to add any shoes there.

On Cloudrunner 2 Heel stack
Test results
Cloudrunner 2 33.6 mm
Average 33.7 mm
Compared to 304 running shoes
Number of shoes
7.6 mm
Heel stack
45.7 mm

Forefoot stack

The forefoot is also moderately stacked at 25.1 mm by today's standards, making it an excellent, reliable choice for daily runs.

On Cloudrunner 2 Forefoot stack
Test results
Cloudrunner 2 25.1 mm
Average 25.0 mm
Compared to 304 running shoes
Number of shoes
7.6 mm
Forefoot stack
36.9 mm

Drop

On claims the Cloudrunner 2 features a 10-mm heel-to-toe drop, but our lab measurements—taken in accordance with official World Athletics guidelines—indicate a slight discrepancy, showing an 8.5 mm drop instead. We are content with this finding as this is a negligible difference.

For us, running on an 8.5-mm or 10-mm drop doesn't significantly alter the running experience, as both are mid-to-high offsets that generally suit all types of footstrikes, though they may be particularly advantageous for heel strikers in our view.

On Cloudrunner 2 Drop
Test results
Cloudrunner 2 8.5 mm
Average 8.7 mm
Compared to 304 running shoes
Number of shoes
-0.8 mm
Drop
16.1 mm

Insole thickness

Previously, we noted that the Cloudrunner 2 adopts an average design philosophy, and the insole perfectly exemplifies this approach. Its 4.7 mm thickness is typical, embodying the essence of "standard."

On Cloudrunner 2 Insole thickness
Test results
Cloudrunner 2 4.7 mm
Average 4.5 mm
Compared to 300 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.

Many runners found the first-generation On Cloudrunner to be too firm and unresponsive, with a durometer hardness of 31.2 HA. This has significantly improved in the latest model.

On has now incorporated its Helion instead of Zero Gravity foam—a good change—and we measured it at 27.3 HA using our Shore A durometer—noticeably softer than before. While it may still seem firm to some, it's important to remember that On's CloudTec design enhances the compression of the midsole, offering a softer sensation underfoot compared to the average midsole design.

Does this mean that the Cloudrunner 2 feels super plush? Not exactly. Like most On models, it leans towards the firmer side compared to cloud-like foams, but we think it's more balanced than its predecessor.

On Cloudrunner 2 Helion

Finally, we'd like to address a point, as On describes the shoe as featuring "Helion superfoam." However, Helion isn't a superfoam for us but rather an improved standard foam that blends EVA with Olefin. Its performance is comparable to other quality training foams, such as the FF Blast+ found in the ASICS Nimbus 26, and it's far away from On's advanced, Pebax-based Helion HF foam featured in the Cloudmonster Hyper.

On Cloudrunner 2 Midsole softness
Test results
Cloudrunner 2 27.3 HA
Average 21.4 HA
We use an average of four tests. The photo shows one of those tests.
Compared to 232 running shoes
Number of shoes
8.5 HA
Midsole softness (soft to firm)
41.5 HA

Difference in midsole softness in cold

We just said that Helion foam is not merely standard EVA; it's a blend of EVA and Olefin. This composition was key during our evaluations, especially since EVA foams typically harden a lot in cold conditions.

Yet the Cloudrunner 2 showed remarkable resilience in our cold-temperature tests. It stiffened by just 16.5% after spending 20 minutes in our freezer. While it may not match the energy return of superfoam, it certainly performs like one in freezing temperatures!

On Cloudrunner 2 Difference in midsole softness in cold
Test results
Cloudrunner 2 16.5%
Average 25.5%
Compared to 231 running shoes
Number of shoes
0%
Difference in midsole softness in cold
100%

Rocker

The Cloudrunner 2 offers a classic, natural ride, diverging from recent trends seen in many brands—a move we highly commend. While rockered shoes have their place, we believe that adopting an overly curved profile for the Cloudrunner would have been a misstep.

On Cloudrunner 2 Rocker

Stability

Lateral stability test

While On markets the Cloudrunner 2 as a stability shoe, we believe it's actually between the neutral and mild stability categories. We saw that it incorporates some supportive features, yet it predominantly functions as a neutral trainer.

Torsional rigidity

One aspect where the Cloudrunner leans more toward a neutral design rather than stability is its torsional rigidity. As previously demonstrated with the outsole evaluation, it features multiple grooves that enhance flexibility.

Additionally, the absence of the Speedboard plate contributes to a moderate score of 3 out of 5 in our torsional rigidity test.

Test results
Cloudrunner 2 3
Average 3.2
Compared to 283 running shoes
Number of shoes
1
Torsional rigidity
5

Heel counter stiffness

The heel counter on this model is notably robust, resembling those found in dedicated stability shoes, with a maximum stiffness rating of 5/5.

This feature is particularly beneficial for heel strikers with pronation issues, providing excellent support. However, it may cause discomfort for runners with sensitive Achilles tendons.

Test results
Cloudrunner 2 5
Average 2.8
Compared to 267 running shoes
Number of shoes
1
Heel counter stiffness
5

Midsole width in the forefoot

Now it's time to delve into the dimensions of the Cloudrunner 2. Our measurements show a width of 117.9 mm, slightly suggesting it as a mild support shoe since it's broader than many neutral trainers.

Nonetheless, as the market trends towards increasingly wider designs, this dimension does not particularly stand out as exceptional.

On Cloudrunner 2 Midsole width in the forefoot
Test results
Cloudrunner 2 117.9 mm
Average 113.7 mm
Compared to 305 running shoes
Number of shoes
100.5 mm
Midsole width in the forefoot
126.5 mm

Midsole width in the heel

The heel mirrors the forefoot, being just slightly wider than a typical neutral shoe. This dimension, along with the extremely rigid heel counter, makes it a solid choice for those seeking a supportive heel experience.

On Cloudrunner 2 Midsole width in the heel
Test results
Cloudrunner 2 93.8 mm
Average 90.5 mm
Compared to 305 running shoes
Number of shoes
74.9 mm
Midsole width in the heel
106.6 mm

Flexibility

Stiffness

One peculiar aspect of the original Cloudrunner was undoubtedly its stiffness, primarily due to the Speedboard plate which On has traditionally been hesitant to remove in some models. However, we're pleased to see that they are finally phasing out this TPU plate in shoes where it didn't made in any sense.

In fact, our tests show a decrease in stiffness from 34.2N for the predecessor to just 21.1N, a change that aligns much better with a shoe designed for versatility and comfort in a variety of activities beyond running.

Test results
Cloudrunner 2 21.1N
Average 29.2N
We use an average of four tests. The video shows one of those tests.
Compared to 287 running shoes
Number of shoes
2.2N
Stiffness
94.4N

Difference in stiffness in cold

We conducted another 20-minute freezer nap to evaluate the shoe's stiffness under extreme winter conditions. The results showed that it required 34.8% more force to flex the shoe afterward, significantly reducing its flexibility in cold weather. 

Test results
Cloudrunner 2 34.8%
Average 35.9%
Compared to 287 running shoes
Number of shoes
0%
Difference in stiffness in cold
148%

Size and fit

Toebox width at the widest part

We conducted our initial measurement in the toebox at its widest part to gauge the space inside. We recorded just 97.8 mm, a typical design approach for this Swiss brand, known for not creating particularly roomy uppers.

On Cloudrunner 2 toebox

While most runners will find this size adequate, those with very wide feet may find it restrictive. In such cases, we recommend the Nike Pegasus 41, which offers a slightly broader fit and it's a fantastic workhorse.

On Cloudrunner 2 Toebox width at the widest part
Test results
Cloudrunner 2 97.8 mm
Average 98.4 mm
Compared to 305 running shoes
Number of shoes
89.5 mm
Toebox width at the widest part
109.1 mm

Toebox width at the big toe

The big toe area also proved to be spacious, alleviating one of our major concerns based on previous designs by On. We measured it at 78.9 mm, which is an average result.

Additionally, the vertical space within the toebox was sufficient. Although the mesh isn't particularly stretchy, it never felt constrictive, allowing for comfortable toe movement.

On Cloudrunner 2 Toebox width at the big toe
Test results
Cloudrunner 2 78.9 mm
Average 78.2 mm
Compared to 179 running shoes
Number of shoes
60.4 mm
Toebox width at the big toe
92.5 mm

Tongue: gusset type

The tongue is partially gusseted to the sides of the shoe, providing secure lockdown without being overly restrictive. This design aligns perfectly with our expectations for a daily trainer that's positioned well above the entry-level price range, ensuring both comfort and security even at faster paces.

On Cloudrunner 2 Tongue: gusset type
Test results
Cloudrunner 2 Both sides (semi)

Comfort

Tongue padding

The tongue of the Cloudrunner 2 features impressive padding, composed of two main foam slabs with a third layer created by folding one of these at the top.

On Cloudrunner 2 tongue

We measured the total thickness at 9.0 mm. This design is ideal for runners who prefer their laces as tight as possible and comfort over everything else, as it prevents lace bite and accommodates a cozy fit.

On Cloudrunner 2 Tongue padding
Test results
Cloudrunner 2 9.0 mm
Average 5.6 mm
Compared to 302 running shoes
Number of shoes
0.5 mm
Tongue padding
14.2 mm

Heel tab

Staying true to On's latest design cues, we found no finger-loop heel tab on the Cloudrunner 2, giving the rearfoot area a cleaner look.

On Cloudrunner 2 Heel tab
Test results
Cloudrunner 2 None

Removable insole

The insole of the Cloudrunner 2 can be easily replaced with an aftermarket one if desired, as it's not glued to the last.

On Cloudrunner 2 Removable insole
Test results
Cloudrunner 2 Yes

Misc

Reflective elements

We've always believed that brands have a significant opportunity to enhance visibility by incorporating reflective branded logos on running shoes—and this time, On has checked the box!

Test results
Cloudrunner 2 Yes