Lightest Backpacks (40L+): Top 20

Lightest first, out of 96 listed (outliers excluded).

1. 1. Montbell Versalite Pack 40 — 480 g
2. 2. Yamatomichi ONE — 554 g
3. 3. Yamatomichi ONE Custom Edition — 554 g
4. 4. Gossamer Gear G4-20 Ultralight 42 Backpack — 627 g
5. 5. Montbell Mesh Gear Pack 50 — 680 g
6. 6. Trail Bum HAULER — 750 g
7. 7. Montbell Balance Light 40 — 780 g
8. 8. Trail Bum HAULER SPECTRA — 790 g
9. 9. Durston Kakwa 40 — 795 g
10. 10. ZEROGRAM Lundy LT 50 — 830 g
11. 11. Hyperlite Mountain Gear Junction — 858 g
12. 12. Hyperlite Mountain Gear Southwest — 869 g
13. 13. Mountain Hardwear Alakazam 45L Backpack — 876 g
14. 14. Rab Syclon XP 40 — 881 g
15. 15. Hyperlite Mountain Gear Windrider — 882 g
16. 16. Durston Kakwa 55 — 895 g
17. 17. Rab Muon 40 — 895 g
18. 18. Rab Muon 40 ND — 895 g
19. 19. Mountain Hardwear Camp 4 Duffel 45 — 899 g
20. 20. Rab Expedition Kitbag II 50 — 900 g

Compared only with other 40L+ backpacks, which still differ in use and frame design. Lighter does not mean better.