The most fundamental difference here is panel technology. The Hisense 100U65QF uses a Mini-LED LCD panel, while the LG OLED83C5PUA uses OLED. In practical terms, OLED produces perfect blacks and near-infinite contrast by switching individual pixels off entirely, whereas Mini-LED relies on local dimming zones to approximate this — a gap that remains meaningful in dark-room viewing. However, the Hisense counters with a substantially larger canvas at 99.5″ versus 83.5″, which dominates immersion in large living spaces. Both panels share the same 4K resolution and 10-bit color depth, but the LG's smaller screen yields a noticeably higher pixel density of 53 ppi versus 44 ppi, meaning text and fine detail appear slightly sharper up close.
On motion and HDR, the Hisense pulls ahead in two specific areas. Its 144Hz refresh rate outpaces the LG's 120Hz, a difference that matters primarily for gaming and fast-motion content, reducing judder and enabling higher frame-rate input. It also supports HDR10+, the dynamic metadata format that LG's OLED lacks — though in practice, Dolby Vision (supported by both) is more widely available on streaming platforms and delivers comparable scene-by-scene tone mapping. For adaptive sync, both cover AMD FreeSync Premium, but the LG adds Nvidia G-Sync compatibility, giving it broader coverage for PC gamers with Nvidia GPUs.
There is no single winner here — the right choice depends entirely on use case. The LG OLED83C5PUA holds a clear edge in pure picture quality for cinephiles prioritizing contrast and black levels, and its G-Sync support makes it more versatile for PC gaming. The Hisense 100U65QF wins on raw screen real estate, higher refresh rate, and HDR10+ support, making it the stronger choice for viewers who prioritize size and gaming fluidity over absolute contrast performance.