Which is better for gaming?

The B6. It lists 0.1 ms response, VRR, G-Sync, FreeSync Premium and a Game Optimizer. The B46 gives you 120 Hz but no stated gaming extras.

Which has the better picture?

The B6 uses an OLED evo panel and adds Dolby Vision. The B46 is standard self-lit OLED. Both give perfect black, but the B6 is the newer panel.

Can I get a bigger screen than 48 inches?

Only on the B46, which comes in 48, 65, 77 and 83 inches. The B6 is sold in 48 inches only.

Is the B6 worth stepping up to over the B46?

For a 48-inch room, yes. You get a newer panel, Dolby Vision, Dolby Atmos and full gaming support. Step to the B46 only if you need a larger size.

Neither maker states a lifespan here. OLED panels can dim over many years of heavy use. The B6 is two model years newer, so its panel design is more recent.

Do both support 120 Hz?

Yes. Both list a 120 Hz refresh rate, which suits consoles and sports.

LG OLED B46 55" 4K Smart TV vs LG B6 48" OLED TV

Both are LG OLED sets with 4K, 120 Hz and perfect black, so the picture is close. The B6 is the newer 2026 model in a single 48-inch size, with OLED evo panel, Dolby Vision, Dolby Atmos, webOS, FILMMAKER MODE and full gaming support (G-Sync, FreeSync Premium, VRR, 0.1 ms response). The B46 covers more sizes up to 83 inches and four HDMI ports, but its listing is thinner on HDR and gaming detail. Buy the B6 for a 48-inch room and the B46 if you need a larger screen.

Choose the OLED B46 if you want a bigger OLED screen, from 48 up to 83 inches, and four HDMI ports for a console, soundbar and streaming box.
Choose the LG B6 if you are buying a 48-inch set and want the newer panel, Dolby Vision and Atmos, and the full gaming feature set.

Prices

LG OLED B46 55" 4K Smart TV: $499.00 at velnoriaot (last seen Nov 12)