LG UltraFine 5K (27MD5KL-B) Review: Worth Buying Used in 2026?

The verdict, up top

For seven years the LG UltraFine 5K was the monitor Apple told Mac owners to buy. In 2015 it was the only 5K Mac monitor that existed. In 2022 Apple replaced it with the Studio Display and removed it from its store. In 2026 it is a legacy purchase that only makes sense used, for well under $1,200. Newer monitors beat it on almost every specification, many of them for less.

Why it mattered

Apple and LG designed the UltraFine together to fill a gap: the 5K iMac couldn’t be used as a standalone monitor, and MacBook Pro owners had no Retina-density external display. Apple sold the UltraFine on apple.com for years and recommended it alongside new MacBook Pros.

It was the first external 27-inch 5K tuned for macOS. Its resolution, pixel density, colour profile and single-cable charging became the template for everything that followed.

Why it’s dated

The UltraFine was last refreshed in 2019 with Thunderbolt 3. Since then:

• The Studio Display launched in 2022 with a better design, a 600-nit panel, a 12MP camera and six speakers
• Apple’s March 2026 Studio Display refresh moved to two Thunderbolt 5 ports with a downstream port for daisy-chain
• Apple added the Studio Display XDR the same month, with Mini-LED and a 120 Hz panel
• Apple discontinued the Pro Display XDR, and ASUS, Dell and newcomers like Kuycon moved into 32-inch 6K
• BenQ and ASUS released 5K monitors that undercut both Apple options
• LG itself moved on: the UltraFine evo 32U990A is a 32-inch 6K with Thunderbolt 5

The UltraFine 5K hasn’t changed. It still has a plastic body, a 1080p webcam and a stand with 110 mm of height adjustment and tilt but no swivel or pivot. The panel is still sharp and accurate for everyday use; it’s the 2015 hardware around it that has aged.

The Thunderbolt 3 question

Thunderbolt 3 still works with every current MacBook Pro and with the Mac mini and Mac Studio models Apple shipped in September 2026. But buying a Thunderbolt 3 monitor in 2026 means committing to a standard two generations old. Thunderbolt 5 carries three times the bandwidth and enables things like daisy-chaining a second 6K display, which Thunderbolt 3 cannot do.

One clarification, because it is often repeated wrongly: higher refresh rates are not a Thunderbolt 5 feature. 5K at 120 Hz fits within DisplayPort 1.4 with compression, so a Thunderbolt 4 Mac such as the M6 Mac mini drives a 120 Hz Studio Display XDR without trouble. Thunderbolt 5 buys bandwidth for everything else sharing the cable.

When it makes sense

Used, under $1,200. Second-hand UltraFines regularly appear for $800 to $1,200. At that price you get a 218 PPI 5K P3 panel that works with any Mac for about half the cost of a Studio Display.

As a second screen. If you already own a Studio Display, a used UltraFine is a pixel-matched companion that costs far less than a second Studio Display.

As a collector. It is a piece of Mac display history, and it matches the 2015–2020 Mac aesthetic.

When it doesn’t

Don’t buy it new in 2026. Scarce stock has pushed new-unit prices to $1,500–$2,000 or more on Amazon and other marketplaces. At that price the Studio Display ($1,599) is better at everything, and the BenQ MA270S ($999) is dramatically better at almost everything. Paying a premium for a 2015 design makes no sense.

The bottom line

If you want an UltraFine 5K, ignore retail pricing and look on the used market. The core panel still delivers Retina density and accurate P3 colour, but the market has moved on. With $1,500 or more to spend, buy a Studio Display. With around $1,000, a used UltraFine is reasonable, though the new BenQ MA270S is the better buy. See Studio Display vs LG UltraFine 5K, or our Studio Display alternatives round-up for the full field.