Introduction to Compact Flagships

The compact flagship market is crowded with options like the Pixel 9a, Pixel 9, Pixel 9 Pro, iPhone 16E, iPhone 16, iPhone 16 Pro, Samsung Galaxy S25, Xiaomi 15, and now the OnePlus 13S. While researching the OnePlus 13S, I noticed it’s entering a packed space without reinventing anything. Yet, it’s generating hype—likely because it’s OnePlus’s first compact flagship.

Display Comparison of OnePlus 13S Xiaomi 15

The Xiaomi 15 has a slightly larger, taller display, while the OnePlus 13S feels more compact and handy. Xiaomi’s 1.38 mm bezels are symmetrical, which I prefer, while the OnePlus 13S has 1.34 mm bezels on three sides but a larger chin at the bottom.

Display Performance comparison of OnePlus 13S Xiaomi

Side by side, the OnePlus 13S has a warmer tone, noticeable in 8K video, while the Xiaomi 15 is closer to neutral. The Xiaomi’s 12-bit panel offers a wider color gamut than the 10-bit panel on the OnePlus 13S, though 12-bit content is rare, so it’s not a dealbreaker.

Performance and Benchmarks comparison of OnePlus 13S Xiaomi 15

Both phones have Snapdragon 8 Elite, LPDDR5X RAM, and UFS 4.0 storage. The Xiaomi 15 comes in a 12/512GB variant, while the OnePlus 13S offers 12/256GB and 12/512GB. In AnTuTu and Geekbench, the Xiaomi 15 scores higher, but it gets hotter and loses more battery life.

I prefer the OnePlus 13S’s performance. It’s well-tuned, balances thermal efficiency, and delivers solid performance. The Xiaomi 15 could be more conservative to manage heat and reduce throttling.

Battery Life and Charging comparison of OnePlus 13S Xiaomi

The OnePlus 13S offers better battery life, with about 7 hours of screen-on time & 6 to 6.5 hours on the Xiaomi 15. Among compact flagships, the OnePlus 13S leads. Its single-cell graphene battery charges variably—48 minutes with the included 80W charger in the box. The Xiaomi 15 supports 90W charging, taking 53-54 minutes, and includes wireless charging.

Camera Setup comparison of OnePlus 13S Xiaomi 15

The OnePlus 13S has a 50 MP Sony Lytia 700 main sensor, a 2x Samsung JN5 telephoto, and a 32 MP selfie camera. The Xiaomi 15 has a triple 50 MP setup (main, ultrawide, telephoto) and a 32 MP selfie camera.

Design and Build Quality Comparison of OnePlus 13S Xiaomi 15

The OnePlus 13S has an impeccable design for a compact phone. It features premium materials—glass back, aluminum frame—with tight tolerances and excellent fit and finish. The camera module blends seamlessly into the back, looking like a natural extension. I prefer its design over the pricier OnePlus 13 and the cheaper OnePlus 13R. OnePlus nailed it here.

Design Comparison of OnePlus 13S Xiaomi 15

However, the OnePlus 13S resembles an iPhone—so much so that colleagues mistook it for one. The Xiaomi 15 also looks good, with a black camera module and silver frame, but its elements feel less cohesive than the OnePlus 13S. Both use premium glass and metal materials.

Weight and Feel Comparison of OnePlus 13S Xiaomi 15

Side by side, both phones are slim and light. The OnePlus 13S feels lighter in hand, with weight distributed more evenly, while the Xiaomi 15 feels denser, with weight concentrated in the center. When placed flat, the Xiaomi 15 has more camera module elevation than the OnePlus 13S.

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Functional Comparison of OnePlus 13S Xiaomi 15

The Xiaomi 15 offers better functionality: a higher IP rating for water and dust resistance, Xiaomi shield glass (more durable despite scratching), and a Type-C 3.2 port versus the OnePlus 13S’s Type-C 2.0. Both have infrared blasters, but the OnePlus 13S replaces the alert slider with a plus key, which I’ll cover in the software section.