Both are the gold standard for synthetic insulated hoodies, and both get recommended constantly in r/Ultralight and Backpacker magazine — for good reason. The Nano Puff is lighter, packs smaller, and handles moisture better when soaked. The Atom LT is more athletic, breathes better, and wears like a softshell-insulation hybrid.
Arc'teryx Atom LT Hoody
The Atom LT is the better active-use layer; the Nano Puff wins for packability and wet-weather versatility.
Specs Comparison
| Spec | Patagonia Nano Puff Hoody | Arc'teryx Atom LT Hoody |
|---|---|---|
| MSRP | ~$280 | ~$260 |
| Weight (M/L) | 312g / 11 oz | 360g / 12.7 oz |
| Insulation | PrimaLoft Gold 60g | Coreloft Compact 40g |
| Shell Denier | 10d ripstop | 20d Arato |
| Stretch Panels | No | Yes |
| Packability | Packs to fist size | Slightly larger |
Insulation and Warmth
The Nano Puff uses PrimaLoft Gold 60g insulation throughout. The Atom LT uses Coreloft Compact 40g in the body with stretchy Torso zone side panels, which trades some warmth for breathability.
In static conditions, the Nano Puff is warmer. Under aerobic load, the Atom LT's zones prevent overheating — a real advantage on the trail.
Weather Resistance
Patagonia's Nano Puff uses a DWR-treated 10-denier ripstop shell that handles light rain and drizzle well. The PrimaLoft insulation retains warmth even when wet.
Arc'teryx treats the Atom LT's face fabric similarly, but the thinner shell doesn't repel rain quite as long. Both need re-DWR treatment after heavy use.
Fit and Athleticism
The Atom LT fits trimmer through the shoulders and torso, making it easier to layer under a shell. The Nano Puff runs slightly boxier and is more comfortable as a standalone insulator.
For climbing, skiing, or fast hiking, the Atom LT's stretch panels under the arms are noticeably freeing. The Nano Puff doesn't restrict movement badly, but it's not built for high-output movement.
Price and Packability
The Nano Puff retails around $280 and packs into its own chest pocket. The Atom LT is $260 and packs down smaller than a down jacket but not quite as small as the Nano Puff.
Both are worth the price for serious use. The Nano Puff has an edge if pack space is critical.
Patagonia Nano Puff Hoody Strengths
- Packs into its own chest pocket — genuinely compressible
- PrimaLoft Gold retains warmth better when wet
- Lighter at ~312g vs Atom LT's ~360g
Arc'teryx Atom LT Hoody Strengths
- Stretch side panels allow full range of motion during activity
- Trims under a hardshell without bunching
- Better breathability during aerobic output
Patagonia Nano Puff Hoody Weaknesses
- Less breathable under aerobic load — you'll overheat on climbs
- Boxier fit doesn't layer under a shell as cleanly
Arc'teryx Atom LT Hoody Weaknesses
- Not as warm in static cold conditions as the Nano Puff
- Atom LT's thinner shell shows wear faster at the cuffs
Best For
- a: Backpackers, travelers, and anyone needing a lightweight wet-weather layer
- b: Climbers, skiers, and active hikers who need breathability and stretch
FAQ
Which is warmer, the Nano Puff or Atom LT?
The Nano Puff is warmer at rest due to its higher fill weight. The Atom LT manages heat better during activity thanks to its stretch panels.
Can either jacket be worn as a standalone in cold weather?
Both work as standalone layers down to around freezing with moderate activity. Below that, you'll want a shell or additional insulation.
Does Arc'teryx's warranty cover the Atom LT?
Yes — Arc'teryx offers a limited lifetime warranty on manufacturing defects. Patagonia offers an Ironclad Guarantee with repairs and replacements.