Keen Seek Trail Runner vs On Running Cloudultra 2
Weight and specs compared for 2026 — and which one to choose.
Trail runners with wide toe box and high cushioning for technical terrain.
Full details →Ultra trail shoe with CloudTec cushioning for long distances.
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Keen Seek Trail Runner vs On Running Cloudultra 2: which should you buy?
If saving weight is your priority, the Keen Seek Trail Runner wins — at 307 g it is 313 g (50%) lighter than the On Running Cloudultra 2 (620 g). That said, the heavier option may justify the extra grams with more capacity, durability or comfort, so weigh the trade-off against how you'll use it.
See where both rank against everything else in this category on the lightest footwear page, or browse the full gear weight database.