The Unstoppable Workhorse: Our In-Depth Review of the On Cloudultra 3

For every glorious finish line, there are a thousand unglamorous miles. There are the pre-dawn starts when the world is still asleep, the rain-soaked slogs through muddy forests, and the back-to-back long runs that test the very limits of your endurance. This is the grind. It's the foundation upon which every ultramarathon, every triathlon, every personal best is built. And for the grind, you don’t just need a shoe; you need a partner. You need a workhorse.

For years, the Swiss maestros at On have captivated us with their revolutionary designs and sleek, urban aesthetic. But a quiet criticism has often followed them onto the trails: were they more style than substance? Were their shoes truly built for the rugged, unforgiving world of high-mileage trail running?

Well, clear your mind of any preconceptions. The game has just changed. With the launch of the On Cloudultra 3, released today, the 3rd of July 2025, the brand isn't just releasing a new shoe; it's making a powerful statement. This isn't a minor tweak or a fresh lick of paint. This is a ground-up redefinition of what a long-distance trail shoe can be. On has strategically created a formidable two-pronged attack on the ultra scene: the featherlight, race-ready Cloudultra Pro for the podium chasers, and its tougher, more dependable sibling, the Cloudultra 3, for the rest of us.

This is the shoe designed for the vast majority of your miles. It’s the reliable, durable, and supremely stable companion engineered to get you through the hardest training blocks, so you can arrive at the start line stronger, fresher, and ready to fly. We’ve delved deep into the tech, analysed the performance, and stacked it up against the titans of the trail. Is this the workhorse you’ve been waiting for? Let’s find out.

Deconstructing the Machine: A Deep Dive into the Tech

To understand what makes the Cloudultra 3 a potential game-changer, we need to look under the bonnet. On has thrown its most advanced technology at this shoe, creating a complex system where every single element has a purpose. It’s a synthesis of cutting-edge materials and intelligent design, all focused on one goal: creating the ultimate high-mileage trainer.

Here are the vital statistics at a glance:

The Upper: Your All-Day Sanctuary

The first point of contact with any shoe is the upper, and for an ultra-distance shoe, it’s arguably one of the most critical components for long-term comfort. On has moved away from conventional designs and opted for a sophisticated Engineered Leno Weave. Imagine a material that’s tough as nails in the high-wear areas where you scrape against rocks and branches, yet incredibly breathable and quick-drying in others. That's the magic of this zoned construction. It’s your personal climate control system, managing moisture from sweat on a hot day and shedding water after an unexpected stream crossing, helping to keep blisters at bay.

Structural integrity is provided by tough TPU overlays that wrap around the midfoot, locking you in place without creating pressure points. This is combined with the sock-like construction that On fans will be familiar with, creating a seamless, foot-hugging feel that minimises internal movement.

Now, let's talk about fit, a historically contentious point for On. Early Cloudultra models were notoriously narrow. Thankfully, On has listened. The Cloudultra 3 continues the trend of its predecessor towards a more accommodating fit, especially in the forefoot, giving your feet room to swell naturally over a 100-mile race. Interestingly, the FlipRelease™ toggle found on previous models is gone. This signals a newfound confidence from the designers; they believe the new upper is so well-engineered that you no longer need extra gadgets to perfect the fit.

The Midsole: The Engine of a Paradoxical Ride

Welcome to the engine room. The midsole of the Cloudultra 3 is where the real innovation lies, and it’s built around a fascinating paradox. The shoe is marketed as being "overcushioned," yet its defining characteristic is a "planted, firm ride." How can it be both?

The answer lies in Helion™ HF hyper foam. This isn't just any foam; it's On's premier Pebax-based super foam, the same high-performance compound found in their elite road racing shoes like the Cloudboom Echo 3. Its inclusion here is a massive upgrade. Unlike the softer, bouncier version in the race-day Cloudultra Pro, the foam in the Cloudultra 3 is a denser, more robust application.

Think of it like the suspension in a World Rally Championship car versus a luxury saloon. The saloon is soft and plush, ironing out every bump. The rally car's suspension is also incredibly advanced and protective, but it's firm, stable, and designed to keep the driver connected to the road for maximum control at speed. The Cloudultra 3 is the rally car. The 32 mm stack of dense Helion™ HF provides a huge amount of protection from sharp rocks and the cumulative impact of thousands of foot strikes, but it doesn't give you that sinking, marshmallow-like feeling. Instead, it provides a stable, responsive, and incredibly efficient platform.

This foam works in concert with two other key pieces of On technology. The embedded TPU Speedboard® acts like a chassis, providing torsional rigidity (to stop the shoe from twisting on uneven ground) and a propulsive, rockered feel that helps you roll smoothly and efficiently from heel to toe. Furthermore, the midsole is designed to cup your foot, seating you inside the foam walls rather than just on top of them. This simple geometric trick dramatically enhances the feeling of stability and control, making you feel at one with the shoe.

The Outsole: Finally, On's Answer to Its Greatest Weakness

Let’s be honest. For years, the biggest complaint levelled against On shoes, both on the road and trail, was their uncanny ability to collect rocks. The open channels of the CloudTec® design were like magnets for pebbles and trail debris, leading to that infuriating stop-start-flick-a-stone-out routine.

The Cloudultra 3 puts that legacy to bed. The Missiongrip™ outsole has been completely overhauled using a data-driven process called Finite Element Analysis (FEA). This is the same high-tech computer simulation used to design aeroplane wings and Formula 1 cars. On's engineers virtually tested hundreds of lug patterns to find the optimal shape and placement for grip while simultaneously designing out the channels that trapped debris.

The result is a thing of beauty. A new profile of multi-directional lugs promises unreal traction across all terrains—from hard-packed fire roads to technical, slippery descents. It’s a design that bites into the trail with newfound confidence. This isn't just an improvement; it's a revolutionary leap that finally addresses the brand's most significant performance flaw, elevating the Cloudultra 3 into a truly top-tier trail contender.

Hitting the Trails: How Does It Actually Feel?

Technical specifications are one thing, but the real test is how a shoe performs out in the wild. Based on its design philosophy and technical makeup, a very clear performance profile for the Cloudultra 3 emerges.

Cushioning & Ride: The Unrelenting Engine

The on-trail experience is defined by that unique firm cushioning. This is not the shoe for runners who want to feel like they’re running on clouds (ironically). It is a protective and brutally efficient system. The dense Helion™ HF foam and the rocker geometry work together to create a smooth, rolling sensation that helps you maintain momentum with less effort. This is a benefit that pays huge dividends deep into an ultramarathon when fatigue is screaming at you to slow down. The shoe is designed to keep your legs feeling fresher for longer, not by coddling them in softness, but by promoting an efficient, propulsive stride.

One crucial thing to note is what we might call a "biomechanical break-in period." This doesn't mean the shoe's materials need to soften. It means you, the runner, might need a few miles to adapt to its unique ride. The combination of a firm plate, dense foam, and a pronounced rocker can feel a little stiff or clunky at first. But once you find your rhythm and settle into your pace, the shoe's propulsive nature comes alive. It's a system you learn to work with, and once you click, it feels incredibly effective.

Stability & Control: A Platform of Confidence

If the Cloudultra 3 has a superpower, it's stability. In the latter stages of a long race, when your form breaks down and your legs are turning to jelly, stability is what keeps you upright and moving forward safely. The Cloudultra 3 delivers this in spades. This sure-footedness doesn't come from old-fashioned stability posts but is baked into the shoe's very DNA.

It’s a trifecta of features working in harmony: the wide, solid base of the midsole provides a huge landing zone; the cupped heel and midfoot design cradle your foot securely; and the inherent firmness of the Helion™ HF foam prevents excessive compression or twisting. The TPU Speedboard® reinforces this, adding a layer of predictable control. This makes the shoe an incredibly reliable choice for technical terrain and for any runner who knows their form gets a bit sloppy when they’re tired.

Traction & Versatility: The All-Terrain Promise

Thanks to the new FEA-optimised Missiongrip™ outsole, this shoe is a true all-rounder. The promise of excellent grip across a spectrum of surfaces appears to be delivered. Whether you're on dry, dusty fire roads, loose gravel, wet rock, or sloppy mud, the new lug configuration is designed to give you the confidence to let rip.

This enhanced traction makes the Cloudultra 3 exceptionally versatile. It’s positioned as an "everyday trail trainer," and for once, that marketing line rings true. This is a shoe you can rely on for the bulk of your training—long runs, recovery jogs, and high-mileage weeks—across whatever unpredictable terrain your adventures take you on.

Sizing, Fit, and Finding Your Perfect Match

A word of advice forged from years of community feedback: if at all possible, try this shoe on before you buy it. On shoes have a well-earned reputation for running a little smaller and narrower than competitors like Hoka or Brooks. To avoid disappointment and ensure you get the comfort needed for ultra distances, we strongly recommend considering going up at least a half-size from your usual brand. Finding the right fit is paramount, and it's worth the extra effort.

Once you have the correct size, the comfort is one of security and protection. The Engineered Leno Weave upper hugs the foot reassuringly, preventing slippage and inspiring confidence on technical ground. It’s a comfortable shoe, but the comfort comes from its secure lockdown, not from plush, step-in softness.

The Verdict: Is the On Cloudultra 3 Your Next Trail Partner?

The On Cloudultra 3 is a bold, highly specialised, and brilliantly executed trail shoe. It’s a significant statement of intent from the brand, but its very specific character means it won't be for everyone. The decision to invest will hinge entirely on your personal preferences for ride feel and stability.

✅ The Good (Strengths)

• Exceptional Stability: Its defining feature. The combination of the cupped midsole, firm foam, and wide Speedboard® creates a supremely confident platform, perfect for long days and tired legs.

• Durable Workhorse Build: This shoe is engineered to take a beating. The robust upper and substantial midsole promise excellent longevity, making it a sound investment for a high-mileage training block.

• Game-Changing Traction: The new Missiongrip™ outsole is a massive leap forward. It provides versatile, high-performance grip, finally solving On's Achilles' heel.

• Protective & Efficient Ride: While firm, the ride is highly protective. The rocker geometry and energetic foam create an efficient feel designed to reduce fatigue over epic distances.

• Aesthetic Appeal: It's an On shoe, after all. The sleek, modern design looks just as good at the post-run café as it does on a mountain summit.

❌ The Not-So-Good (Potential Weaknesses)

• Polarising Firm Ride: This will be the deal-breaker. If you love a soft, plush, "marshmallow" feel, you will likely find the Cloudultra 3 too firm and unforgiving.

• Premium Price Point: At £180, this is a top-tier price for a non-carbon-plated trainer. It's a significant investment, placing it against some very established and often cheaper competitors.

• Substantial Weight: At 295g for a men's size 9, it's no lightweight racer. This reinforces its identity as a steady, reliable workhorse, not a nimble speedster.

• Fit Nuances: The historical tendency for On shoes to run narrow means finding the perfect fit might be a challenge, especially for runners with wider feet.

The Showdown: Cloudultra 3 vs. The Competition

No shoe lives in a bubble. The most telling comparison is against the king of the trail workhorses: the Hoka Speedgoat. The choice between these two shoes is a choice between philosophies. The Speedgoat is the benchmark for soft, maximalist cushioning. It’s a plush, forgiving ride. The Cloudultra 3 is the firmer, more stable, and more propulsive alternative. If you want to sink into your cushioning, choose the Speedgoat. If you want a stable platform that gives you energy back, the Cloudultra 3 is calling your name.

This launch also positions On brilliantly within its own ecosystem. The Cloudultra 3 (the Trainer) and the Cloudultra Pro (the Racer) create a perfect partnership. You do your hard, high-volume training in the durable, stable Cloudultra 3. Then, on race day, you switch to the lighter, softer, and faster Cloudultra Pro for peak performance. It’s a professional-level strategy now available to all runners.

Who Is The On Cloudultra 3 For?

This shoe is an outstanding choice for the trail runner who:

• Prioritises stability and a protective ride above all else.

• Is training for an ultramarathon or embarking on a high-mileage block.

• Prefers a firmer, more connected-to-the-ground feel that provides good energy return.

• Is willing to invest in a premium, durable product.

• Has been waiting for On to finally make a serious trail shoe that doesn't trap rocks.

Who Should Look Elsewhere?

This shoe is likely NOT the right choice for the trail runner who:

• Loves and actively seeks out soft, plush, maximalist cushioning.

• Prefers a lightweight, nimble shoe for shorter, faster races.

• Is on a strict budget.

• Has very wide feet and has struggled with On's fit in the past.

In conclusion, the On Cloudultra 3 is a triumph of focused engineering. It confidently carves out its niche as a supremely stable, protective, and efficient high-mileage workhorse. It leverages On’s latest technology to address past flaws while doubling down on the firm, propulsive ride that is central to the brand’s identity. It won’t be the shoe for every runner, but for the athlete seeking an unwavering partner for the long, hard grind, the On Cloudultra 3 is a formidable and compelling new contender for the trail-running crown.