Sony's Xperia Z5 Compact is almost of the same size as Apple's iPhone 6s, and can be considered as a challenger to one another in terms of screen size.  Concerning the other aspects of the phones, here is a straight and simple comparison.

Apple iPhone 6s, in terms of design,  portrays a more elegant appeal.  There is no doubt that the metal unibody plus the rounded edges of the iPhone 6s greatly enhances its appearance, aside from the fact that it gives a very comfortable feeling to the user when holding the phone. A fingerprint scanner is fused into the home button, which is a very functional feature. Users can also choose from four colors, Space Gray, Gold, Rose Gold and Silver.    

Sony Xperia Z5 Compact, on the other hand, is largely made out of plastic, but it gives a solid grip to its user. The fingerprint sensor is located on the side, together with the power button.  However, the Sony Xperia Z5 Compact has its own benefits with regard to design.  It is IP68 certified, the highest rating for waterproof and dustproof certification. The phone also offers four colors, black, white, coral and yellow.

Sony Xperia Z5 Compact and iPhone 6s screens of both phones are almost identical in every aspect.  The iPhone 6s is a 4.7-inch 750 x 1334 resolution and offers 326 ppi density, GSM Arena reported.  The Sony Xperia Z5 Compact is 4.6-inches, offers a resolution of 720 x 1280 with a 323 ppi density.

Underneath the casings, the iPhone 6s is powered by a dual-core Apple A9 clocking at 1.84 GHz, a PowerVR GT7600 for the GPU, plus a 2 GB RAM.  The storage is at a fixed capacity of 16, 64 and 128 GB. Meanwhile, the Sony Xperia Z5 Compact offers an octa-core Qualcomm Snapdragon 810 chipset at a speed of 1.5 Ghz and 2.0 Ghz, plus an Adreno 430 for the GPU and a 2 GB RAM, Phones Review reported.  The phone is equipped with a microSD slot and is expandable up to 200 GB.

The iPhone 6s costs $199 with a two-year contract, while the Sony Xperia Z5 Compact is at $650, unlocked.