On Cloudmonster Void review

The On Cloudmonster Void is a good option for:

• Runners who loved the first-gen Cloudmonster and want the same platform in a more lifestyle-ready package that can still handle short, easy runs.
• Those who care more about clean design and premium build quality than top-tier performance numbers.
• People looking for a versatile shoe that works at the gym, out to dinner, or during daily errands, while still being capable of daily runs.

The price of the Cloudmonster Void will be a deal-breaker for many runners. We found in the lab that its performance numbers sit around average, yet the cost lands in the premium tier. From our perspective, if you want a solid daily trainer without stretching your budget, the ASICS Novablast 5 or the Nike Vomero 18 offer a more value-packed experience.

We also think that high-mileage runners chasing serious cushioning should look elsewhere. On our runs, the shoe felt limited in range and energy return. In our view, the Nike Vomero Plus (or Premium if you go all in!) or the New Balance 1080 v15 are superior picks.

The On Cloudmonster Void offers a solid underfoot foundation, delivering reliable shock absorption with 129 SA in the heel and 108 SA in the forefoot.

While it may not feel as groundbreaking as On suggests on its website, it remains more than adequate for short, easy runs, which is exactly the type of effort this shoe is designed to handle.

Energy return does not set any benchmarks either, but again—performance is not the main goal of this shoe. With 55.5% in the heel and 58.4% in the forefoot, we believe that it's good enough to for those casual runs. Still, given its premium price tag, we expected slightly stronger numbers in this area.

The Cloudmonster Void is based on the original Cloudmonster (not the Cloudmonster 2) so we already had a clear idea of what to expect.

Back then, the Cloudmonster felt like a true maximalist option for most runners. However, with 35.9 mm in the heel, that is no longer the case. What once qualified as max stack has now become simply average by today’s standards.

The forefoot even falls below our current lab average, measuring just 25.1 mm of stack height.

This makes it a versatile option and prevents the shoe from feeling overly bulky, which also helps when wearing it for everyday activities or at the office.

To get along with the Cloudmonster Void, you need to feel comfortable in a high heel-to-toe drop setup, as we measured 10.8 mm. That places it clearly on the higher end of the spectrum and makes it more naturally suited for heel strikers.

As is often the case with On shoes built on Helion foam, the Cloudmonster Void delivers a firm sensation, measuring 29.1 HA in our durometer test. However, the distinctive CloudTec midsole geometry softens the perception slightly.

That said, the overall ride still leans clearly toward the firmer side, so you need to be comfortable with that type of underfoot feel. Despite its appearance, this is far from a plush, sink-in experience.

The rocker is moderate and starts relatively late, encouraging smooth transitions while avoiding an overly aggressive rolling sensation.

In our view, this geometry aligns well with a shoe built to balance casual wear and easy running, since a highly rockered midsole could feel unnatural and uncomfortable during everyday use.

On has decided to retain the Speedboard plate, crafted from the same plasticky material. Its role here is mainly to enhance support rather than to deliver a strong propulsion effect. Indeed, propulsion is certainly not the defining characteristic of this shoe.

Although the Void keeps the same midsole platform found in the original Cloudmonster, On has reworked the upper to better match the lifestyle-oriented purpose of this version.

Runners with wide feet will likely see this as good news, as we measured a generous 97.2 mm at the forefoot. That added space translates into a more accommodating fit and makes the shoe noticeably more inviting for broader foot shapes.

The toebox also measured above our lab average in the second assessment of the gel mold taken from the shoe’s interior, which aligned with our expectations.

However, there is a caveat regarding the fit. The redesigned upper sits slightly low over the toes, which tends to create a polarizing sensation that you may enjoy or strongly dislike depending on your preferences.

If you are sensitive to pressure across the top of the toes or prefer a more relaxed fit, the Void is unlikely to suit you.

We were pleased with the outcome of our wet concrete grip test. A score of 0.62 indicates reliable traction in dry and rainy conditions alike, reinforcing the Cloudmonster Void as a versatile option.

The outsole leaves part of the Speedboard plate exposed (yes, it's a rock catcher) and incorporates a central channel running from heel to toe, which helps shave weight while trying promoting a more flexible ride.

We counted 11 pods in total. Most are covered with rubber, while three located in lower-abrasion areas rely on Helion foam and do not feature a rubber coating.

With a Speedboard plate embedded in the midsole, we initially expected the Cloudmonster Void to feel overly stiff. However, it never came across as uncomfortable during our runs, and our lab result of 13.6N confirms that it sits below the average in longitudinal stiffness.

The Void version features an upper that prioritizes casual wear and step-in comfort over running performance, and that shift results in a slight weight increase, bringing it to 10.2 oz or 289g. By current standards, that figure is far from impressive.

Compared to the standard Cloudmonster, the Void’s upper is positioned as more lifestyle-oriented and less performance-driven as expected. However, that shift does not come at the expense of airflow.

In our lab test, the shoe earned a 4/5 in breathability, which we consider the sweet spot for a versatile, year-round option. It provides enough ventilation for warm days without feeling overly airy in cooler conditions, so you do not have to overthink your sock choice.

Ventilation is clearly noticeable in the toebox, where airflow is consistent and effective. On also added 24 fully perforated holes in the tongue, helping keep the instep cool and preventing heat buildup during longer wear.

Under the microscope, the upper left little to criticize. On continues to deliver strong build quality and reliable materials, and that standard is maintained here.

Overall, we see the upper as one of the highlights of the Void, combining comfort, clean aesthetics, and effective ventilation in a well-balanced package.

There are no changes from a stability standpoint, as the Cloudmonster Void remains a neutral shoe.

However, it presents an interesting setup in this area, blending support-oriented features such as the Speedboard plate and high sidewalls with a relatively compact landing platform and no noticeable heel flare. As a result, we prefer to classify it strictly as a neutral option.

It did not surprise us to measure high torsional rigidity, considering the firm foam and the presence of the Speedboard plate. Even with the full-length guidance line running from heel to toe, the shoe resists twisting noticeably, earning a 4/5 in our assessment.

The heel counter of the Cloudmonster Void follows a straightforward, no-frills design and earns a 3/5 in our test, striking a balanced blend of structure and comfort.

We mentioned earlier that the midsole felt on the narrower side, and our caliper measurement confirms it.

At 109.9 mm in the forefoot, it sits below the current average. We know that this geometry will appeal to runners who dislike overly wide maximalist platforms but still want solid shock absorption underfoot.

That same design approach carries into the heel, where we measured just 86.8 mm. This narrow base further explains why the shoe is not ideal for heel strikers who require added support during runs. However, for walking or casual use around town, it's not a problem at all.

We appreciated the engineered mesh chosen by On, as it delivers a comfortable and breathable feel. In addition, our durability test yielded a solid 3/5, which is nice, especially considering that this special Void version also includes a generously sized toe bumper for added protection.

On the flip side, the heel counter earned just a 2/5 in our durability test, which raised some concerns. If you are prone to wearing holes in this area, it is something to keep in mind.

Our durability trifecta concluded with a 0.8 mm indentation in the outsole. That figure is lower than our lab average and highlights strong resilience, easing concerns for those planning to use the Void for all kinds of activities beyond running.

With 3.3 mm of rubber and a strong performance in our durability test, we do not expect premature wear issues in the Cloudmonster Void, even for runners who use it as a sneaker too.

The insole measures a fairly standard 4.3 mm in thickness, so there is nothing particularly noteworthy in this area.

Removing the insole and swapping it for a different option is perfectly doable.

After spending 20 minutes in our freezer, the Cloudmonster Void became 19% firmer. That is a solid result for an EVA-based foam... but there is more to the story.

Helion is a blend of EVA and Olefin copolymers, and that second component plays a key role in maintaining performance in cold conditions.

Adding reflective details is low effort and high reward. In this case, a reflective logo improves safety and doubles as subtle marketing.

We believe that On got it right this time, and we still don’t understand why others keep ignoring something so straightforward.

The lacing system has been completely redesigned, now using partially hidden lace loops that create a much cleaner aesthetic. The laces themselves are also different, coming in thinner than those on the original version.

Since the Cloudmonster Void is intended for longer daily wear beyond running, On increased the tongue padding from 1.0 mm to 3.1 mm. It remains a relatively thin construction, but it delivers noticeably more comfort than before.

The tongue is partially gusseted on both sides, and based on our experience, we believe this design choice works well.

The On Cloudmonster Void does not come with a price increase, which is a relief. Even so, it already sits at a premium level for a daily trainer that does not deliver standout performance.

That said, On’s pricing strategy is well known, and the brand consistently positions itself above many competitors, so this shoe is far from the ideal choice for runners who prioritize value.

The heel follows On’s usual minimalist approach, combining clean lines with functional structure.