Between the α7 IV and α9 III, the α7 IV comes out ahead in weight and megapixels, while the α9 III wins on max video. Overall, the α7 IV scores 52.8 and the α9 III scores 46 on our Mars Score.
Which should you buy?
The α7 IV edges ahead on the Mars Score (52.8 vs 46), but the 6.8-point gap is small enough that the right pick comes down to which spec advantages matter to you.
Pick the α7 IV if you carry the device everywhere and weight or thickness has been the deciding factor before. The biggest gaps in its favor are weight, megapixels.
Pick the α9 III if you care most about max video. Its strongest claims are max video.
Both ship with comparable sensor size, in-body stabilization, af points, so those specs don't separate the two — focus on the differences below.
Bottom line: the α7 IV is the safer default. The other model is the right choice only when its specific advantages line up with your priorities.
Why Sony - α7 IV wins
- ▲Weight — 45.00 g less. 658 vs 703.
- ▲Megapixels — 37.50% more. 33 MP vs 24 MP.
Why Sony - α9 III wins
- ▲Max video: 4K120 (vs 4K60).
Spec comparison
Sensor
| Spec | Sony - α7 IV | Sony - α9 III |
|---|---|---|
| Sensor sizeⓘ | Full Frame | Full Frame |
| Megapixels | 33 MPlead | 24 MP |
| Max ISO | 51200 | 51200 |
Video
| Spec | Sony - α7 IV | Sony - α9 III |
|---|---|---|
| Max video | 4K60 | 4K120lead |
| RAW video | false | truelead |
| Log profileⓘ | true | true |
Autofocus
| Spec | Sony - α7 IV | Sony - α9 III |
|---|---|---|
| AF pointsⓘ | 759 | 759 |
| Eye AFⓘ | true | true |
| In-body stabilizationⓘ | true | true |
Body & Controls
| Spec | Sony - α7 IV | Sony - α9 III |
|---|---|---|
| Weight | 658 glead | 703 g |
| Weather sealedⓘ | true | true |
| Dual card slotsⓘ | true | true |
Frequently asked
Spec-level deep dives
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