The LG OLED B4 is the cheapest route into a genuine OLED. It is dimmer than the flagships at 660 nits and uses last year processing, but it keeps the perfect blacks, four HDMI 2.1 ports and low input lag that make OLED worth buying. At £749 for the 48-inch, it is our best budget pick.
Not everyone needs a flagship, and the LG B4 (the 48-inch is the OLED48B4) exists for exactly that buyer. It sits a step below the C4 in LG range: a less bright panel, an older processor and 40 Gbps rather than 48 Gbps HDMI ports. What it does not compromise on is the thing that makes OLED OLED, the perfect, self-lit blacks and infinite contrast. At £749 for the 48-inch it is the most affordable genuine OLED in the UK, and a brilliant choice for a bedroom, study or gaming desk.
| Model | Price | Panel type | Resolution | Peak brightness (10% window) | Rating | Link | |
|---|---|---|---|---|---|---|---|
 | ★ Top pick LG OLED B4 48-inch (OLED48B4) | £819.00 | OLED (W-OLED, 48-inch) | 4K (3840 x 2160) | 660 nits | ★ 4.4 | View → |
£819.00 £899.00
OLED (W-OLED, 48-inch) · 4K (3840 x 2160) · 660 nits
The verdict from Idris Bello, home cinema and TV tester
The best budget OLED. The B4 uses last year processing and a less bright 660 nit panel, and its HDMI 2.1 ports run at 40 Gbps rather than 48, but it still delivers the perfect blacks and infinite contrast that make OLED worth buying. At £749 for the 48-inch it is the most affordable genuine OLED in the UK, and ideal for a bedroom, study or as a large gaming monitor.
The same inky OLED blacks as the flagships, just with less peak punch in a bright room.
Below is the measured spec sheet for the 48-inch OLED48B4 we tested. Figures come from our own bench data or LG confirmed specifications.
| Panel type | OLED (W-OLED, 48-inch) |
|---|---|
| Resolution | 4K (3840 x 2160) |
| Peak brightness (10% window) | 660 nits |
| Refresh rate | 120 Hz |
| Input lag (1080p/120Hz) | 9.5 ms |
| HDMI 2.1 ports | 4 (40 Gbps) |
| Colour gamut (DCI-P3) | 97.2% |
| Smart platform | webOS 24 |
| Our rating | 4.4 / 5 |
| Typical UK price | £819.00 |
The B4 is the right TV if you want true OLED picture quality on a tighter budget, or a smaller set for a bedroom, study or desk. The 48-inch size suits a viewing distance of around 1.5 to 1.8 m, which makes it ideal as a bedroom TV or a large, gorgeous gaming monitor. Despite the lower price it keeps four HDMI 2.1 ports, 120 Hz, VRR and 9.5 ms input lag, so it is a seriously capable gaming screen. If you have always wanted OLED blacks but balked at flagship prices, this is your entry point.
It is less suited to a bright living room or a buyer chasing maximum HDR impact. At 660 nits it is the dimmest set here, so in a sunlit room highlights have less punch, and its 40 Gbps HDMI ports lack the headroom of the C4 48 Gbps inputs for future formats. If you want more brightness for the same OLED blacks, the LG C4 is the upgrade; if you want a bigger screen for a living room, the Philips OLED809 at 65 inches is worth a look.
The B4 reached 660 nits on a 10% window, around 400 nits less than the C4, so HDR highlights are visibly less intense and it is happiest in a dimmer room. Where it matches its pricier siblings is black level: a true OLED zero, giving the same effectively infinite contrast and inky shadows. Colour covered 97.2 percent of DCI-P3, a hair behind the flagships but still excellent, and out-of-the-box accuracy in Filmmaker Mode was good, with a Delta E around 3. In a normal or dim room, the B4 picture is hard to fault for the money; only in bright daylight does the brightness gap show.
The B4 uses LG a8 processor rather than the C4 a9 Gen 7, so upscaling of poor sources is a touch less refined, but for HD and 4K content the difference is marginal. The panel runs at 120 Hz, handles 24 fps film without judder and, thanks to OLED instant pixel response, keeps fast motion clean.
This is where the B4 punches above its price. We measured 9.5 ms of input lag at 1080p/120Hz, excellent for the money, and it keeps four HDMI 2.1 ports, 120 Hz, VRR with G-Sync and FreeSync, ALLM and the webOS Game Optimiser. The one caveat is the 40 Gbps HDMI bandwidth, which handles 4K/120Hz gaming perfectly well but lacks the headroom of the C4 48 Gbps ports for higher frame rates and future formats. For a PS5, Xbox Series X or PC at 4K/120Hz, it is more than enough.
The B4 runs the same webOS 24 as the C4, so the software experience is identical and fast. The built-in 2.0-channel, 20 W speakers are modest, as you would expect at this size and price, so a soundbar is a worthwhile pairing for films. It supports Dolby Vision and Dolby Atmos.
The B4 two compromises are brightness and HDMI bandwidth. At 660 nits it is the dimmest here, so it is at its best in a controlled-light room rather than a sun-filled one, and its 40 Gbps ports, while fine today, have less future headroom than the flagships. Neither matters in a bedroom, study or dim living room, which is exactly where the B4 belongs.
The B4 is best for the budget-conscious buyer who wants genuine OLED blacks, a smaller 48-inch screen for a bedroom or desk, and strong gaming credentials, without paying flagship money. If you want more brightness for a living room, step up to the LG C4; if you want a big screen, the Philips OLED809 is our large-room pick.
The C4 uses a brighter evo panel (1,065 nits versus 660 nits on the B4 we measured), a faster processor, a 144 Hz refresh rate versus 120 Hz, and 48 Gbps HDMI 2.1 ports versus 40 Gbps on the B4. Both have four HDMI 2.1 ports and the same perfect OLED blacks. The B4 is the value pick; the C4 is the upgrade if you want more brightness and headroom for high-frame-rate gaming.
Yes, surprisingly so for the price. It keeps four HDMI 2.1 ports, a 120 Hz refresh rate, VRR with G-Sync and FreeSync, and we measured 9.5 ms input lag at 120 Hz, which is excellent. The only caveat is the 40 Gbps HDMI bandwidth, which is fine for 4K/120Hz gaming but lacks the headroom of the C4 48 Gbps ports for future formats.
It depends on your distance. The 48-inch suits a viewing distance of around 1.5 to 1.8 m, so it is ideal for a bedroom, study, or as a large gaming monitor at a desk. For a typical living-room sofa at 2.5 m or more, the 55 or 65-inch sizes (the B4 also comes in 65 and 77-inch) will feel more immersive.
The B4 is our best budget pick because it brings the defining quality of OLED, perfect, self-lit blacks and infinite contrast, to the lowest price in the UK at £749 for the 48-inch. It is dimmer than the flagships at 660 nits and its HDMI ports run at 40 rather than 48 Gbps, but it keeps four HDMI 2.1 inputs, 9.5 ms input lag and the same fast webOS as the C4, making it a superb bedroom, study or gaming-desk TV. If your budget can stretch and you want more brightness for a living room, the LG C4 is the natural upgrade. Either way, read our best OLED TV for gaming guide if a console or PC is your main use.