ApoTelyt has updated their CAM-parator app with the Canon EOS R. We have pulled the images comparing the Canon EOS R to both the Sony A7 III and Nikon Z6. The Sony looks to be the smallest of the bunch, with the Canon and Nikon being closer in size, but the Canon a slightly larger grip and overall thickness.
Check out the comparisons below.
Canon EOS R vs Sony A7 III // Click for larger
Canon EOS R vs Nikon Z6 // Click for larger