Where they actually differ
The most decisive specs, ranked by how much they matter — before the full spec table.
| Spec | LG - C5 OLED 55 | TCL - QM6K 65 |
|---|---|---|
| Peak brightness | 1300 nits | 1800 nits |
| Screen size | 55 " | 65 " |
| HDMI 2.1 ports | 4 | 2 |
| Panel type | OLED | Mini-LED |
| Smart OS | webOS | Google TV |
Between the C5 OLED 55 and QM6K 65, the C5 OLED 55 comes out ahead in hdmi 2.1 ports / panel type, while the QM6K 65 wins on peak brightness / screen size. Overall, the C5 OLED 55 scores 66.8 and the QM6K 65 scores 68 on our Mars Score.
Which should you buy?
These two are nearly even on the Mars Score (66.8 vs 68). The decision is not about overall quality — both clear the bar — it is about which specific trade-offs fit your use.
Pick the C5 OLED 55 if you care most about hdmi 2.1 ports / panel type. The biggest gaps in its favor are hdmi 2.1 ports, panel type. The single most decisive one: HDMI 2.1 ports — 2.00 more. 4 vs 2.
Pick the QM6K 65 if the display is what you stare at all day — refresh rate, brightness, or sharpness is where the difference will be most visible. Its strongest claims are peak brightness, screen size, smart os. The single most decisive one: Peak brightness — 38.46% more. 1800 nits vs 1300 nits.
Both ship with comparable refresh rate, dolby vision, vrr, so those specs do not separate the two — focus on the differences below.
Bottom line: there is no wrong answer here — match the spec advantages to how you actually use the product. The Mars Score parity says both are well-rounded; the differences are about trade-offs, not quality.
Which should you buy: LG - C5 OLED 55 or TCL - QM6K 65?
TCL - QM6K 65 leads the current Mars Score by 1.2 points.The more useful decision is the trade-off behind that result: compare screen size, panel type, hdmi 2.1 ports against the way you will actually use the product.
Choose LG - C5 OLED 55 if…
LG - C5 OLED 55 has the measurable edge on hdmi 2 1 count, panel type.
Choose TCL - QM6K 65 if…
TCL - QM6K 65 has the measurable edge on peak brightness nits, screen size in, smart os.
This is a structured comparison of the published catalog values. It is not a claim of identical real-world performance across every workload; use the linked spec drill-downs and methodology page to inspect the inputs.
Why LG - C5 OLED 55 wins
- ▲HDMI 2.1 ports — 2.00 more. 4 vs 2.
- ▲Panel type: OLED (vs Mini-LED).
Why TCL - QM6K 65 wins
- ▲Peak brightness — 38.46% more. 1800 nits vs 1300 nits.
- ▲Screen size — 18.18% more. 65 " vs 55 ".
- ▲Smart OS: Google TV (vs webOS).
Spec comparison
Display
| Spec | LG - C5 OLED 55 | TCL - QM6K 65 |
|---|---|---|
| Screen size | 55 " | 65 "lead |
| Panel typeⓘ | OLEDlead | Mini-LED |
| Resolutionⓘ | 4K | 4K |
| Refresh rateⓘ | 144 Hz | 144 Hz |
| Peak brightnessⓘ | 1300 nits | 1800 nitslead |
HDR & Smart
| Spec | LG - C5 OLED 55 | TCL - QM6K 65 |
|---|---|---|
| Dolby Visionⓘ | true | true |
| HDR10+ⓘ | false | truelead |
| Smart OS | webOS | Google TVlead |
| Dolby Atmosⓘ | true | true |
Gaming
| Spec | LG - C5 OLED 55 | TCL - QM6K 65 |
|---|---|---|
| HDMI 2.1 portsⓘ | 4lead | 2 |
| VRRⓘ | true | true |
| ALLM | true | true |
Frequently asked
Which is brighter, C5 OLED 55 or QM6K 65?+
QM6K 65 peaks at 1800 nits vs 1300 nits.
Which is better for gaming, C5 OLED 55 or QM6K 65?+
C5 OLED 55 offers 144Hz refresh and 4 HDMI 2.1 ports.
Does C5 OLED 55 or QM6K 65 support Dolby Vision?+
Both support Dolby Vision.