Ergotron's LX and HX are two of the most recognizable single monitor arms on the market, and they look like close relatives. Both are desk-mounted, both use Ergotron's patented Constant Force technology for light-touch adjustment, and both are designed to lift your screen off the desk so you can position it where you are most comfortable. The difference comes down to what you plan to put on them.
This comparison uses the specifications from our product listings for the Ergotron LX Desk Mount Single Monitor Arm and the Ergotron HX Desk Monitor Arm. Where a detail is not listed in a product description, we say so rather than guess.
Quick answer: Choose the Ergotron LX for a typical office monitor that weighs between 7 and 25 lbs and is up to 27 inches, especially if you want a proven, easy-to-install arm with flexible clamp and grommet mounting. Choose the Ergotron HX for large, heavy screens, including big ultrawide and curved displays, since it is listed for monitors up to 42 lbs and screens up to 49 inches.
Ergotron LX vs. HX at a Glance
| Specification | Ergotron LX Desk Mount Single Monitor Arm | Ergotron HX Desk Monitor Arm |
|---|---|---|
| Weight capacity | 7 to 25 lbs (3.2 to 11.3 kg) | Up to 42 lbs (19.1 kg) |
| Screen size | Single monitor up to 27-inch screen size | Up to 49" |
| Motion technology | Constant Force technology | Patented Constant Force Technology |
| Mounting | Desk Clamp (surface edge .4" to 2.4" thick) or Grommet Mount (holes .31" to 2" wide, up to 3" thick) | Desk mount; clamp details not listed in product description |
| VESA | 100 x 100 mm and 75 x 75 mm | Not listed in product description |
| Notable features | Installs from above the desk; arm folds over base; white, silver or black finishes | Rotation stop on base; cables hidden under arm and through extension; BIFMA level 2 certified |
Ergotron LX Desk Mount Single Monitor Arm
The LX is Ergotron's everyday workhorse. Its listing describes Constant Force technology that lets you adjust "height, tilt, and angle to suit your needs without wobbling or bouncing," and supports "a single monitor up to 27-inch screen size."
Its weight capacity is listed as "7 to 25 lbs (3.2 to 11.3 kg)," with an important note: "With monitors greater than 20 lbs (9.1 kg) in weight, the vertical range of motion may be reduced up to 4.5" (11 cm) for a total height range of 8.5" (22 cm)." In other words, the LX performs across its full range with lighter displays and gives up some vertical travel near the top of its capacity.
Mounting flexibility is a strong point. The LX lists a Desk Clamp that "attaches to surface edge .4" to 2.4" (10 to 60 mm) thick" and a Grommet Mount that "attaches through surface holes .31" to 2" (8 to 50 mm) wide and up to 3" (76 mm) thick." It supports VESA "100 x 100 mm & 75 x 75 mm" hole patterns, and Ergotron notes it "installs entirely from above the desk surface." You can also "Fold the arm over the base to fit under storage shelves or cabinets in tight areas."
Pros
- Well matched to common office monitors up to 27 inches
- Clamp and grommet mounting options with listed thickness ranges
- Installs from above the desk
- Folds over the base for tight spaces
- Available in white, silver or black finishes
Cons
- Listed maximum of 25 lbs rules out many large or heavy displays
- Vertical range may be reduced with monitors over 20 lbs
- Minimum listed weight of 7 lbs means very light screens may not balance well
- Note: when installed on WorkFit-T or WorkFit-TL, the listing says the maximum monitor weight is reduced to 14 lbs and a separately ordered Grommet Mount (98-017) is required
Want a deeper look? Read our full Ergotron LX Monitor Arm review.
Ergotron HX Desk Monitor Arm
The HX is built for big screens. Its listing says it "can easily reposition large monitors weighing up to 42 lbs (19.1 kg)," with a display size of "Up to 49"." That puts large ultrawide and super-ultrawide monitors within reach of a single desk-mounted arm.
Like the LX, it "Offers ergonomic monitor positioning using patented Constant Force Technology." The HX adds a practical detail for cubicle users: a "rotation stop on the base" to "Avoid hitting cube walls." Cables "stay hidden under the arm and through the extension," and the arm is "BIFMA level 2 certified for a low environmental and social impact."
Pros
- Listed for monitors up to 42 lbs and screens up to 49 inches
- Constant Force adjustment for heavy displays
- Rotation stop helps protect cubicle walls
- Integrated cable management
- BIFMA level 2 certified
Cons
- More arm than you need for a typical 24- or 27-inch office monitor
- Product description does not list minimum weight, VESA pattern or clamp range, so check those details before ordering
Key Decision Factors
Weigh your monitor. This is the most important step. Find your monitor's weight without its stand, and add any accessories such as a webcam or light bar. If the total is between 7 and 25 lbs and the screen is 27 inches or smaller, the LX is a natural fit. If it exceeds 25 lbs, the HX is the Ergotron option of these two listed for heavier loads.
Consider screen size and shape. Large ultrawide and curved screens are where the HX's listed capacity of "Up to 49"" stands out.
Check your desk. The LX lists specific clamp and grommet ranges, so you can confirm compatibility with a tape measure. For the HX, review mounting details before you buy, or contact us for help.
Not sure which arm suits your display? Our Monitor Arm Finder can help you narrow it down.
Who Should Choose Which
Choose the Ergotron LX if: you have a standard office monitor up to 27 inches weighing 7 to 25 lbs, want flexible clamp or grommet mounting, and like a choice of finishes.
Choose the Ergotron HX if: you use a large, heavy monitor up to 42 lbs or a screen up to 49 inches, work in a cubicle where a rotation stop helps, or want integrated cable routing for a big display.
Frequently Asked Questions
Can the Ergotron LX hold an ultrawide monitor?
The LX listing specifies support for "a single monitor up to 27-inch screen size" and a weight capacity of "7 to 25 lbs." Most large ultrawide monitors fall outside that range, which is where the HX's listed "Up to 49"" capacity comes in.
Do both arms use the same adjustment technology?
Both listings describe Ergotron's Constant Force technology, which is designed to let you move the monitor with a light touch and have it stay in place.
Which arm is better for a sit-stand desk?
Either can work on a sit-stand desk if your monitor falls within its listed capacity. Note that the LX listing reduces maximum monitor weight to 14 lbs when installed on WorkFit-T or WorkFit-TL.
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