Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | Boox - Note Air 4 C | Boox - Tab Ultra C Pro |
|---|---|---|
| Storage | 64 GB | 128 GB |
| Weight | 420 g | 480 g |
Between the Note Air 4 C and Tab Ultra C Pro, the Note Air 4 C comes out ahead in weight, while the Tab Ultra C Pro wins on storage. Overall, the Note Air 4 C scores 77.7 and the Tab Ultra C Pro scores 84.3 on our Mars Score.
Which should you buy?
The Tab Ultra C Pro edges ahead on the Mars Score (77.7 vs 84.3), but the 6.6-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the Note Air 4 C if you carry the device everywhere and weight or thickness has been the deciding factor before. The biggest gaps in its favor are weight. The single most decisive one: Weight — 60.00 g less. 420 vs 480.
Pick the Tab Ultra C Pro if you care most about storage. Its strongest claims are storage. The single most decisive one: Storage — 100.00% more. 128 GB vs 64 GB.
Both ship with comparable screen size, resolution, waterproof, so those specs do not separate the two — focus on the differences below.
Bottom line: the Tab Ultra C Pro is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Which should you buy: Boox - Note Air 4 C or Boox - Tab Ultra C Pro?
Boox - Tab Ultra C Pro leads the current Mars Score by 6.6 points.The more useful decision is the trade-off behind that result: compare storage, weight against the way you will actually use the product.
Choose Boox - Note Air 4 C if…
Boox - Note Air 4 C has the measurable edge on weight g.
Choose Boox - Tab Ultra C Pro if…
Boox - Tab Ultra C Pro has the measurable edge on storage gb.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why Boox - Note Air 4 C wins
- ▲Weight — 60.00 g less. 420 vs 480.
Why Boox - Tab Ultra C Pro wins
- ▲Storage — 100.00% more. 128 GB vs 64 GB.
Spec comparison
Display
| Spec | Boox - Note Air 4 C | Boox - Tab Ultra C Pro |
|---|---|---|
| Screen size | 10.3 " | 10.3 " |
| Resolution | 300 ppi | 300 ppi |
| Color screen | true | true |
| Warm light | true | true |
Design
| Spec | Boox - Note Air 4 C | Boox - Tab Ultra C Pro |
|---|---|---|
| Weight | 420 glead | 480 g |
| Waterproof | false | false |
| Page-turn buttons | false | false |
Storage & Battery
| Spec | Boox - Note Air 4 C | Boox - Tab Ultra C Pro |
|---|---|---|
| Storageⓘ | 64 GB | 128 GBlead |
| Battery life | 3 weekslead | 2 weeks |