Ergotron LX vs HX vs MX: Which Monitor Arm Is Right for Your Setup?
Ergotron makes three of the best single-monitor arms on the market — the LX, HX, and MX. They look similar, cost differently, and serve different displays. Here's a head-to-head on capacity, reach, and the curved-monitor caveats.
If you’re shopping for a monitor arm, you’ve probably noticed that Ergotron makes about half the well-reviewed arms on the market. Three models dominate the single-monitor lineup: the LX, the HX, and the MX. They look almost identical from across the room, cost meaningfully differently, and each is built for a specific weight and screen size range.
This post is the comparison that took us several mounts to figure out. Here’s the short version, the spec breakdown, and which arm to pick for which monitor.
Quick Verdict by Monitor Type
- 24–32 inch flat or curved, under 19 lbs: Ergotron LX ↗ (Amazon Associates). The default, the most common, the one you should buy if you don’t have a reason to upgrade.
- 32–43 inch curved or heavy-gaming, 20–42 lbs: Ergotron HX ↗ (Amazon Associates). The upgrade path for heavy ultrawides.
- 38–49 inch ultrawide or super-ultrawide, up to 42 lbs: Ergotron MX ↗ (affiliate). Long reach, low post profile, premium build.
Ergotron LX — The Default
The LX is Ergotron’s mid-range single-arm and the best-selling monitor arm in the western market. It uses Ergotron’s Constant Force tension system (an internal spring mechanism that holds position without thumbscrews) and supports monitors from 7 to 19 lbs.
Spec sheet:
- Weight capacity: 7–19 lbs (3.2–8.6 kg)
- Screen size: up to 34” (Ergotron’s official spec; we’ve successfully mounted 38” ultrawides under 19 lbs)
- Vertical adjustment: 13” range
- Reach (from pivot to screen): 25”
- Tilt: 75° (back) / 5° (forward)
- Pan: 360°
- Rotation: portrait/landscape
- VESA: 75×75, 100×100
- Warranty: 10 years
- Color: matte black, polished aluminum, white
Where the LX excels:
- Constant Force tension is genuinely set-and-forget. Once tuned to your monitor, it stays in position for years.
- Mounting hardware accommodates both desk clamp (1.4”–2.4” desktop thickness) and grommet mount (0.4”–2.4”).
- Replacement parts are available individually, and the warranty is honored without drama.
Where it falls short:
- 19 lb capacity is below many heavy 32-inch curved gaming monitors. The MSI MAG 321CUP weighs 22 lbs; LG 45GR95QE-B weighs 36 lbs. Both are too heavy.
- Reach is 25” — adequate for desks 27”+ deep, marginal for shallow desks.
Buy: Ergotron LX (matte black) on Amazon ↗ (Amazon Associates). Polished aluminum and white finishes are available; pricing is identical.
Ergotron HX — Heavy-Duty Single
The HX uses the same Constant Force mechanism but with a stronger spring and beefier joints. Capacity nearly doubles to 42 lbs.
Spec sheet:
- Weight capacity: 20–42 lbs (9–19 kg)
- Screen size: up to 49”
- Vertical adjustment: 13” range
- Reach: 25”
- Tilt: 75° / 5°
- Pan: 360°
- Rotation: portrait/landscape
- VESA: 100×100, 200×100, 200×200
- Warranty: 10 years
- Color: matte black, polished aluminum, white
Where the HX excels:
- Handles the heaviest single-monitor setups on the market. We’ve mounted a 36-lb Samsung 49-inch ultrawide on an HX for two years; no sag.
- Supports VESA 200×200, which most large displays require.
- Same intuitive Constant Force tension as the LX.
Where it falls short:
- For monitors under 20 lbs, the HX is overkill. The Constant Force spring requires a minimum load to work properly — a 12-lb monitor on an HX may droop or fail to hold position.
- Costs ~50% more than the LX.
Buy: Ergotron HX on Amazon ↗ (Amazon Associates).
Ergotron MX — Long Reach, Premium Build
The MX is the premium pick. Same Constant Force system, but the build is meaningfully nicer — milled-aluminum joints rather than cast, a longer reach arm, and a low-profile post designed for tight under-shelf clearance.
Spec sheet:
- Weight capacity: 6–30 lbs (2.7–13.6 kg)
- Screen size: up to 32” (modern variant; older MX supports up to 24”)
- Vertical adjustment: 13” range
- Reach: 35” (longest of the three)
- Tilt: 70° / 5°
- Pan: 360°
- Rotation: portrait/landscape
- VESA: 100×100
- Warranty: 10 years
- Color: matte black, polished aluminum
Where the MX excels:
- 35” reach is genuinely useful for desks where the monitor needs to push back further than the LX/HX can reach (deep desks, wall-mount-style setups).
- Low post profile (~11 inches above desktop) clears under-shelf and overhead lighting setups better.
- Material quality is noticeably better in person than LX/HX.
Where it falls short:
- VESA 100×100 only — won’t mount the largest displays.
- 30 lb capacity caps it below the HX.
- Costs about 2x the LX.
Buy: Ergotron MX direct ↗ (affiliate).
The Decision Tree
Ask three questions in order:
- Is your monitor over 19 lbs? If yes → HX. If no, continue.
- Do you need over 25 inches of reach? If yes → MX. If no, continue.
- Do you have a budget constraint? → LX.
99% of single-monitor home office users buy the LX. The HX is for heavy ultrawide or large display users. The MX is for users with specific reach/clearance requirements or premium-materials preferences.
Curved Monitor Caveats
Curved monitors complicate VESA mounting. The center of gravity is closer to the screen face than on a flat monitor, which puts unusual torque on the arm joint.
- For curved monitors with 1500R or shallower curvature, no adjustment needed.
- For 1000R or deeper (like Samsung Odyssey or LG UltraGear curved): consider a VESA spacer adapter. The standard Ergotron mount works but the screen tilt range is reduced.
- 49” super-ultrawide curved displays: HX only, and use a VESA reinforcement plate. The pivot point is far enough from the screen center to create persistent sag without a reinforcement.
Dual-Monitor Setups
None of these arms is a dual-monitor arm by default. For dual monitors, see:
- Ergotron LX Dual Side-by-Side ↗ (Amazon Associates): two LX arms on one post. Best for two 24-inch monitors.
- Ergotron LX Dual Stacking ↗ (Amazon Associates): vertical stacking, useful for trading-style setups.
- For two monitors over 19 lbs each: two separate HX arms, mounted independently.
What About Non-Ergotron Alternatives?
Several brands compete with Ergotron:
- Herman Miller Flo Plus: Cleaner aesthetic, more expensive, capacity is 22 lbs (between LX and HX).
- Humanscale M2.1/M8.1: Best-in-class joint smoothness, very expensive, lower capacity than Ergotron’s lineup.
- Fully Jarvis: Budget alternative, ~$100 cheaper than LX, build quality is one step below.
- Amazon Basics Premium Monitor Arm: Surprisingly competent for the price (~$80), but only 17 lbs capacity and shorter warranty.
For most users, Ergotron is the right pick — the LX in particular. The 10-year warranty, parts availability, and the Constant Force mechanism are difficult to beat at the price.
Related Reading
- How to choose a monitor arm — the full buying decision
- VESA compatibility explained — mounting patterns and adapters
- Sister site StandDeskReview ↗ — for the desks these arms attach to
- Sister site ErgoRanker ↗ — for spec-driven ergonomic rankings
Final Word
If you’re stuck deciding between Ergotron LX, HX, and MX, the answer is almost certainly the LX. The HX exists for heavy ultrawides; the MX exists for long-reach and premium-material requirements. Most home offices need neither.
Specs verified May 2026. Pricing is approximate manufacturer/Amazon listing as of publication.
Where to buy
Below are Amazon listings for products covered in this article. Prices and stock vary by region; check the UPLIFT ↗, Fully ↗, FlexiSpot ↗, or manufacturer direct pages for warranty registration and configuration options not available on Amazon.
- BenQ ScreenBar Halo — View on Amazon ↗
- Topo Anti-Fatigue Mat (Ergodriven) — View on Amazon ↗
- Ergotron HX Monitor Arm — View on Amazon ↗
- Ergotron LX Monitor Arm — View on Amazon ↗
- Ergotron MX Monitor Arm — View on Amazon ↗
- Fully Cooper Monitor Arm — View on Amazon ↗
- Fully Jarvis Bamboo Standing Desk — View on Amazon ↗
- Herman Miller Flo Monitor Arm — View on Amazon ↗
- HON Ignition 2.0 Chair — View on Amazon ↗
- Humanscale 6G Keyboard Tray — View on Amazon ↗
- Humanscale M2.1 Monitor Arm — View on Amazon ↗
- Jarvis Monitor Arm (Single) — View on Amazon ↗
- Vari Electric Standing Desk — View on Amazon ↗
Disclosure: Some links above are affiliate links. If you purchase through them, we may earn a small commission at no extra cost to you. Our recommendations are based on spec analysis and hands-on review, not commission rates.
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