Below you can see the front view size comparison of Fujifilm X-T30 and Sony A7 III. Fujifilm X-T30 is clearly the smaller of the two cameras. Its body is 9mm narrower, 13mm shorter and 27mm thinner than Sony A7 III.
Fujifilm X-T30 vs Sony A7 III - Front View
Fujifilm X-T30 vs Sony A7 III - Top View
The chart below depicts how two cameras compare with average dimensions of the cameras in their class.
Camera Size Comparison
Select Two Cameras for Size Comparison