Listen to the verdict
A monitor arm does two things at once: it lifts your screen to the right height (top of the display near eye level, so you stop craning your neck) and it reclaims the desk the monitor's stock foot was hogging. The buy comes down to three checks. First, fit: your monitor needs a VESA pattern (75×75 or 100×100 mm) and must sit inside the arm's weight range — the number people get wrong. Second, how often you move it: a gas-spring arm repositions with one hand and is worth it if you switch sit/stand; a cheaper fixed-height arm is fine if the screen stays put. Third, one screen or two: a dual arm for a matched pair, two singles for mixed sizes or heavier panels. The Ergotron LX is the boring right answer for a single standard monitor; size up to a heavy-duty arm for a big ultrawide. Most arms include both a clamp and a grommet fitting, so mounting is rarely a dealbreaker.
Ergotron's official installation video
Ergotron's own video walks through mounting and adjusting the LX arm — the clamp fit, the gas-spring tension, and how the range of motion works. It is manufacturer marketing rather than an independent review, but it is the clearest look at what the mechanism actually does.
Two problems, one product. The first is height: a monitor on its stock foot usually sits too low, so you spend the day looking down and craning your neck. An arm floats the screen up so the top of the display lands near your eye line — the same ergonomic win a laptop stand gives a laptop, but for a full monitor and with far more adjustment.
The second is desk space. A monitor's factory stand plants a wide foot in the most useful part of the desk. An arm clamps to the back edge and cantilevers the screen out over that space, handing you back the area in front of the monitor and letting you push the screen back, pull it forward, tilt, swivel or rotate it to portrait. On a small desk, or any two-screen setup, that reclaimed space and freedom of position is often the real reason people buy one.
Five criteria, in the order that affects daily desk life:
Gas-spring (CF patented) · up to ~34" / ~11.3 kg · VESA 75&100 · clamp + grommet included · full tilt/swivel/rotate
This is the arm most people should buy for a single standard monitor, because it does the job — float the screen anywhere, hold it rock still, reclaim the desk — better and more durably than anything cheaper. The patented constant-force gas spring means you nudge the monitor to any height or depth with one hand and it simply stays there; there are no pole notches to fight and nothing to re-tighten every week. It clamps to the desk edge (or bolts through a grommet, both fittings in the box), fits 75 and 100 mm VESA, and tilts, swivels and rotates to portrait. Build quality is the reason it is the reference arm: aluminium, smooth motion, and it does not sag over time. Pair it with a raised screen at eye level and an external keyboard and you have the textbook ergonomic desk.
Where it is not the pick: it is rated for standard monitors up to about 34", so a big heavy ultrawide or large curved panel needs the heavy-duty option below. And if your screen never moves, a cheaper fixed arm saves money. For two screens, see pick 3.
Gas-spring · typically 17–32" / up to ~9 kg · VESA 75&100 · clamp + grommet · cable management
You do not have to pay premium money for a solid single arm. A well-reviewed budget gas-spring arm gets you most of the Ergotron's benefit — one-handed float, tilt, swivel, portrait rotation, both mounting fittings — for noticeably less, and for a normal 24–32" monitor that is genuinely all most people need. The things to check on a cheaper arm: a stated weight range that comfortably brackets your monitor (so it neither floats nor sags), a metal (not plastic) build at the joints, and a real gas spring rather than a stiff mechanical hinge. Get those right and a budget arm holds position well and moves smoothly.
Trade-off: fit, finish and long-term sag resistance won't match the reference arm, and the cheapest models vary batch to batch. Favour a reputable brand and read the weight range carefully rather than buying the lowest listing blind.
Two screens on one base · gas-spring · each arm typically up to ~9 kg · VESA 75&100 · single clamp
If you run two similarly sized monitors side by side, a dual arm on one base is the tidy, cost-effective answer. Both screens hang off a single clamp, stay aligned, and each side still tilts, swivels and floats independently so you can angle the pair into a shallow arc around you. It is usually cheaper than buying two separate single arms and uses only one spot on the desk edge. Match it to your monitors' combined VESA and per-arm weight rating, and check the total load your desk edge can take with two screens cantilevered out.
Trade-off: a single base is less flexible than two independent arms if your monitors are different sizes or one is heavy — in that case, two singles (or one single plus a heavy-duty arm) place and support mismatched screens better. For a matched pair, though, the dual arm is the right call.
Larger spring · rated for ~34–49" ultrawide / heavier weight · VESA 100 (often 200) · reinforced clamp
A big ultrawide, a large curved panel, or a heavy professional display outweighs what a standard arm is built for, and putting one on the wrong arm makes it sag and drift within days. A heavy-duty arm solves that with a bigger gas spring, a stronger and wider desk clamp, and a higher weight ceiling, so a 34–49" screen floats and holds just like a normal monitor does on a standard arm. Confirm both the maximum screen size and the maximum weight against your specific display — and check the VESA pattern, since some large monitors use 200 mm spacing or need an adapter. This is the arm to buy for the setup in our ultrawide monitor guide.
Trade-off: heavier, bulkier and pricier than a standard arm, and overkill for a normal 24–27" monitor. Only size up to this if your screen genuinely needs it — but if it does, do not compromise with a lighter arm.
| Pick | Screens | Screen size | Adjust | Best for |
|---|---|---|---|---|
| Ergotron LX ★ | Single | Up to ~34" | Gas-spring | Most single-monitor desks |
| Budget gas-spring | Single | ~17–32" | Gas-spring | Best value single arm |
| Dual arm | Two | Matched pair | Gas-spring | Side-by-side two-screen |
| Heavy-duty ultrawide | Single | ~34–49" | Gas-spring | Big / heavy screens |
Almost every returned monitor arm comes down to one of two mismatches, so confirm both first. VESA pattern: look at the four mounting holes on the back of your monitor — the spacing is almost always 75×75 mm or 100×100 mm, and the arm's plate must match (larger monitors sometimes use 200 mm). If your monitor has no VESA holes at all, you need a separate VESA adapter bracket made for that model.
Weight range: a gas-spring arm has both a minimum and a maximum. Under the minimum, the spring pushes the screen up and it won't stay down; over the maximum, it sags and drifts. Weigh your monitor (the spec sheet lists it) and pick an arm whose range comfortably brackets it — not one where your screen sits right at the top or bottom of the range. Get VESA and weight right and the rest is easy.
Does a monitor arm fit my monitor? Almost certainly, if it has a VESA mount and falls within the arm's weight range. Check that the VESA hole pattern on the back (usually 75×75 or 100×100 mm) matches the arm's plate, and that your monitor's weight sits inside the arm's stated range. Weight is where people go wrong — a gas-spring arm has a minimum and a maximum, so a very light screen floats up and a heavy or ultrawide one sags. No VESA holes means you need a separate adapter bracket.
Clamp mount or grommet mount — which is better? A C-clamp is easier and the default: it grips the back edge of the desk with no drilling and can be repositioned. A grommet bolts through a hole in the desktop for a more permanent, slightly sturdier fix. Use a clamp unless your desk has no usable back edge or a top outside the clamp's thickness range. Most quality arms include both fittings, so you rarely have to choose at purchase.
Do I need a gas-spring monitor arm? For daily height changes, yes. A gas-spring arm holds the monitor wherever you nudge it and repositions with one hand, which is ideal if you switch between sitting and standing or share the desk. A cheaper mechanical arm with fixed pole heights costs less and is fine if you set the screen once and rarely move it. Pay for the gas spring if you reposition often; save it if the screen stays put.
Single or dual monitor arm for two screens? For two identically sized, moderate-weight monitors, a dual arm on one base is tidier and usually cheaper than two single arms and keeps both aligned. Two independent single arms give more freedom to place each screen and handle mismatched sizes or heavier panels better, at the cost of two clamps. Dual for a matched pair; two singles for mixed sizes or maximum freedom.
Can a monitor arm hold an ultrawide or a heavy monitor? Yes, but match the arm to the load. Standard arms handle common 24–32" monitors; a 34–49" ultrawide, big curved panel or heavy professional display needs a heavy-duty arm with a larger spring and stronger clamp — confirm both the maximum screen size and weight in the specs. An ultrawide on a standard arm sags and drifts. When in doubt, size up rather than run a standard arm at its limit.
Ergotron LX — our best pick for a single-monitor desk
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