Elegoo Mars 4 Ultra review

Why I would buy the Ultra, and why I would also buy the plain Mars 4

The honest answer is that both are good. The Mars 4 and the Mars 4 Ultra share the same 18 micron LCD panel, the same footprint, the same generation of machine. The differences between them are real but they are not large enough to make one a clearly superior purchase in every situation.

What I can say is that the tempered glass screen protection on the Ultra is the feature I value most in that gap. The base Mars 4 has a bare LCD. The Ultra does not. If you are careful and confident with resin handling, the base Mars 4 is fine. If you are a first-time buyer still learning what careful looks like, the $20 jump to the Ultra buys something worth having.

What it is and what it is not

The Mars 4 Ultra is a Gen 4 18 micron printer released in 2023. Build volume is 153 x 77 x 165 mm, which is 10 mm shorter on the Z axis than the base Mars 4’s 175 mm, a difference that will never matter for standard miniature printing. The screen runs at 18 microns, identical to the base model.

What it adds over the base Mars 4: tempered glass on the LCD, WiFi for file transfer, ACF film instead of nFEP, and .cbt slicer format support alongside the standard .goo files. What it does not add: auto-levelling, a tilting VAT, auto-material handling, or any of the smart features on the Mars 5 Ultra above it.

This is still a basic printer. No app required, no cloud account, no smart features beyond WiFi. That is appropriate for what this machine is.

What it gets right

The tempered glass is the standout upgrade and the reason I lead with it. An LCD screen on a resin printer is the component you most want to protect. Spilling resin onto a bare screen is a risk every time you pour or remove the VAT. Tempered glass means that a careless moment does not immediately become an expensive replacement. For experienced printers who have done this hundreds of times, the risk feels abstract. For someone handling resin for the first time, the protection is genuinely reassuring.

The .cbt format is a more technical upgrade but it is relevant if print quality is a priority. The base Mars 4 saves in the .goo format, which has known anti-aliasing limitations. The Mars 4 Ultra can save in .cbt instead, which handles anti-aliasing properly and produces smoother curved surfaces on the final print. For anyone who has noticed the difference between aliased and anti-aliased edges on a curved surface at 28mm scale, this is worth caring about.

ACF film produces slightly lower peel force per layer than nFEP. In practice this means marginally better release on fine overhanging detail. It is not a dramatic difference but it is real, and on a machine printing at 18 microns where fine detail is the point, marginal improvements to release are welcome.

What it does not get right

The Z height reduction from 175 mm to 165 mm is a strange choice. It is unlikely to affect real printing sessions, since most miniature and terrain prints sit comfortably under 165 mm. But it is an odd step backwards on a premium variant, even if the practical impact is near zero.

The ACF film is the right choice for print quality but it is slightly more expensive to replace than standard nFEP. Over a year of regular printing, the difference is modest. Over several years of heavy use, it adds up.

The Mars 5 Ultra complicates the buying decision above this machine. The tilting VAT on the 5 Ultra is a real speed improvement, not a marketing feature. If the budget stretches and print throughput matters, the question of whether to buy the 4 Ultra or save towards the 5 Ultra is a legitimate one.

Honest verdict

The Mars 4 Ultra is a sensible buy at $170. The tempered glass alone justifies the $20 premium over the base Mars 4 for most buyers, and the .cbt format support is a meaningful bonus for anyone who cares about anti-aliasing quality. I would not hesitate to recommend it as a first printer.

The Mars 5 Ultra sits above it with the tilting VAT if speed matters and the budget stretches. For buyers whose printing happens once or twice a week and who are not trying to maximise throughput, the Ultra is better value than the 5 Ultra and there is no need to stretch further.

For the full comparison of every current machine at each price point, the resin printer buying guide has the table.

Pros

• 18 micron pixels at $170, which is the cheapest serious miniature-grade resolution has ever sold for in a machine with this build quality.
• Tempered glass screen protector as standard: the single most practically useful upgrade over the base Mars 4.
• Supports the .cbt slicer format, which enables proper anti-aliasing in a way the base Mars 4's .goo files do not.
• ACF film instead of nFEP offers lower peel force per layer, which is a modest but real benefit on fine-detail prints.
• WiFi for file transfer is convenient if your slicer machine is across the room, even if it is not a feature that changes print quality.

Cons

• Build volume is marginally shorter than the base Mars 4 (165 mm vs 175 mm Z height), which rarely matters in practice but is technically a step backwards.
• ACF film is slightly more expensive to replace than nFEP when it eventually wears out.
• No auto-levelling, which is the feature most first-time buyers ask about before discovering it is not as important as they assumed.
• Slow next to the tilting-VAT machines above it in the lineup, although speed was never the point of this machine.
• The Mars 5 Ultra now sits above it with the tilting VAT, which complicates the buying decision for anyone whose budget is flexible.

Who it is for

First-time buyers who want 18 micron pixels and the peace of mind of tempered glass screen protection. Anyone for whom anti-aliasing quality matters enough to care about the .cbt format difference.

Who it is not for

High-volume printers who need speed, or buyers with tight budgets who are fine managing an unprotected screen carefully.

What I would buy instead

If budget is the constraint, the base Mars 4 at $149 gives you the same pixels without tempered glass. If speed matters and the budget stretches, the Mars 5 Ultra has the tilting VAT. The Ultra is a sensible middle ground for most buyers.

Last reviewed 1 May 2026.