Which is lighter, the On Cloudmonster 1 or the Cloudmonster 2?

The On Cloudmonster 1, by 0.7 oz in a men's US 9 (9.7 oz vs 10.4 oz).

Did the price change between the On Cloudmonster 1 and the Cloudmonster 2?

Yes. List price went up $10, from $170 to $180. Street prices differ: the older shoe usually sells under list once its successor ships.

Do the On Cloudmonster 1 and Cloudmonster 2 come in the same widths?

Yes. Both run in D for men's sizes, so a width that fit in the Cloudmonster 1 carries over to the Cloudmonster 2.

How do the stack heights compare?

30 mm heel and 24 mm forefoot on the On Cloudmonster 1, against 35 mm and 29 mm on the Cloudmonster 2. That is 5 mm more under the heel and 5 mm more under the forefoot. See the stack height note in the table above: the published figures changed convention mid-lineage.

Is the Cloudmonster 2 still the newest Cloudmonster?

No. The Cloudmonster 3 replaced it in 2026, so the Cloudmonster 2 now sells as an older model and usually below its $180 list price.

On Cloudmonster 1 vs Cloudmonster 2

Updated August 5, 2026. Specs are men's US 9.

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THE SHORT ANSWER

Whichever your size still exists in. The Cloudmonster 1 is discontinued at retail, so remaining pairs sell against a thinning size run, while the Cloudmonster 2 has a full one. The Cloudmonster 1 also lists $10 lower.

On Cloudmonster 1Sizes running outMen's at Amazon Women's
On Cloudmonster 2Sizes running outMen's at Amazon Women's

Availability last checked Aug 5, 2026. Prices and stock change without notice.

Cloudmonster 1 · 2022

Cloudmonster 2 · 2024

Every spec, side by side

Spec	Cloudmonster 1	Cloudmonster 2
FIT AND WEIGHT
Weight	9.7 oz	10.4 oz
	Up 0.7 oz. The original's midfoot cutout under the plate is filled in on the 2, which is where some of that went.
Widths	D	D
Upper	Recycled engineered mesh	Engineered mesh, 92 percent recycled polyester, with a thin gusseted tongue
	The tongue is the weak point. Trail and Kale found nothing anchoring it, so it slid, and lace bite comes up repeatedly in owner reports. It is the specific thing the 3 was built to fix.
CUSHIONING GEOMETRY
Heel stack	30 mm	35 mm
	Treat the 5 mm as the outer bound. On never published a stack height for the original, so the 30/24 figure comes from Believe in the Run and Running Shoes Guru, while other outlets published 33/27 and 29/23 for the same shoe. RunRepeat measured the two pairs 3 mm apart rather than 5, which points at a change in what On counts rather than 5 mm of new foam.
Forefoot stack	24 mm	29 mm
Drop	6 mm	6 mm
MATERIALS
Midsole	Helion superfoam	Dual-density Helion superfoam
	Firmer under load, and split into two densities: a firmer carrier with a softer insert under the forefoot, which is the reverse of the usual arrangement.
Plate	Full-length Speedboard directly under the foot	Nylon-blend Speedboard, lowered away from the foot
VALUE
List price at launch	$170	$180
	Up $10 to $179.95. Trail and Kale called that steep for what the shoe does and argued it belonged nearer $140 to $150.
OTHER CHANGES
Speedboard position	Directly under the foot	Lowered, with foam between the plate and your foot
	The change reviewers point at for the lost bounce. Road Trail Run went from calling the original surprisingly mellow and fun to calling the 2 energy zapping and flat.
Sizing	Standard On sizing	On advised sizing down from the original
	On's own guidance, and testers still found the 2 long. If you own the original, do not assume your size carries over.

Weighing whether to switch at all, rather than which of these two to buy? What replaced the On Cloudmonster 1 covers the verdict on the update, what loyalists made of it, and the closest alternatives from other brands.

Buy the Cloudmonster 1

Sizes running out

Discontinued at retail. Amazon carries what remains, so treat an in-stock size as a closing window, and expect prices to swing.

Men's: Check remaining stock Women's: Check remaining stock

Availability last checked Aug 5, 2026.

Buy the Cloudmonster 2

Sizes running out

Discontinued at retail. Amazon carries what remains, so treat an in-stock size as a closing window, and expect prices to swing.

Men's: Check remaining stock Women's: Check remaining stock

Availability last checked Aug 5, 2026.

Questions runners ask

Which is lighter, the On Cloudmonster 1 or the Cloudmonster 2?: The On Cloudmonster 1, by 0.7 oz in a men's US 9 (9.7 oz vs 10.4 oz).
Did the price change between the On Cloudmonster 1 and the Cloudmonster 2?: Yes. List price went up $10, from $170 to $180. Street prices differ: the older shoe usually sells under list once its successor ships.
Do the On Cloudmonster 1 and Cloudmonster 2 come in the same widths?: Yes. Both run in D for men's sizes, so a width that fit in the Cloudmonster 1 carries over to the Cloudmonster 2.
How do the stack heights compare?: 30 mm heel and 24 mm forefoot on the On Cloudmonster 1, against 35 mm and 29 mm on the Cloudmonster 2. That is 5 mm more under the heel and 5 mm more under the forefoot. See the stack height note in the table above: the published figures changed convention mid-lineage.
Is the Cloudmonster 2 still the newest Cloudmonster?: No. The Cloudmonster 3 replaced it in 2026, so the Cloudmonster 2 now sells as an older model and usually below its $180 list price.