The Elegoo Mars and Mars Pro edge out the Phrozen Sonic Mini with slightly larger build volumes – 120 x 68 x 155 mm to the Sonic Mini’s 120 x 68 x 130 mm. It’s probably a fringe case that anyone should use the full available height, but for those few who do, the Marses have it with an extra 20 mm.

Here’s where the party is at. There’s a gulf of difference between the Sonic Mini and both Mars printers in the LCD tech they use to cure layers of a print, with factors that bring benefits to both sides.

The first big difference is the type of masking LCD screen used, with the Phrozen Sonic Mini using a monochrome LCD – notable for its durability and allowing a greater intensity of light through for quicker cure times – and the Mars and Mars Pro using a standard LCD panel typical of many other budget resin printers.

The Sonic Mini’s panel allows the printer to cure layers of standard 405 nm resin as fast as two seconds flat – a dramatic speed bump over the Mars and its default layer cure time of eight seconds, and the Mars Pro at seven seconds. It’s almost a night and day difference.

Between the three printers and their LCD panels, however, both the Mars and Mars Pro get points for print resolution. Both use 5.5-inch displays boasting 2560 x 1440 pixels resolution, meaning that they offer a pixel size of 0.0047 mm in the X- and Y-axes. The Sonic Mini, at 5.5 inches and 1920 x 1080 pixels resolution, only offers 0.0062 mm.

Where maximum detail counts, Elegoo’s machines win out. If speed and optimum output matter, the Sonic Mini is a class above.

Both the Phrozen Sonic Mini and Elegoo Mars lack any kind of air filtration system. It’s best practice to use MSLA 3D printers in a well-ventilated room, but this goes doubly so for these two.

The Elegoo Mars Pro, however, does come with some form of an air filtration system. Buried in the base unit of the printer, the Mars Pro’s carbon filter goes some way to neutralize the noxious stench associated with exposed resin.

Given the need to open the machine up to remove prints, change resin, clean, and, well, generally just use the printer, you’re wafting the smell around no matter what. When testing we did not have the capability to test the efficacy of the filter so we can only speak to its presence, not performance.

As mundane an accessory as it is, even the resin vats on these three machines are different enough to warrant their own sizable section here.

The Sonic Mini has a plastic tray that adds a vibrant splash of color to the printer. We’ve seen ruminations online of resins fusing with the sidewalls and cracks appearing in this vat after prolonged use. From our time testing it, we did not encounter such problems, but early owners of the machine have probably exceeded our print time with it. Something to keep in mind.

The Elegoo Mars uses your more typical machined metal vat. Chunky, durable, and unremarkable in its utility.

The Elegoo Mars Pro builds on this with a similar, heavy-duty metal for its resin vat, using a (for lack of a better word) gutted design with carved out inner walls that give more room for resin. In addition to being durable, as the plain Mars’ vat is, the Mars Pro’s vat allows the printer to run for longer before needing a top-up of resin.

Measuring these vats against one another, figuratively speaking, the Mars Pro wins hands-down for sheer usefulness.

All three of these budget MSLA printers are compatible with ChiTu’s ChiTuBox slicing software. As such, model preparation and slicing for them are identical.

The software (even downloaded from ChiTu directly, for a clean install) comes with settings profiles for all three, meaning setting up is a simple case of selecting the correct printer from a dropdown list.

Things diverge a little behind the scenes, with the software writing files with different extensions – .phz for the Phrozen Sonic Mini, .cbddlp for the Elegoo Mars, and .ctb for the Elegoo Mars Pro. Slicing the same model for all three printers takes approximately the same amount of time.

Writing a large and complex print job to the printers’ respective file types shows a greater difference, with the Mars Pro’s .ctb file a sixth of the size of the Sonic Mini’s .phz file, which in turn is a tenth of the size of Mars’ .ctddlp. These differences in file size and write time are not a consistent sliding scale, but it’s safe to say the Mars Pro’s .ctb is the lighter and more efficient file to write.

Advantage, Mars Pro (though the Sonic Mini is hot on its heels).

A number of retailers carry the Phrozen Sonic Mini, Elegoo Mars, and Elegoo Mars Pro printers, often with price points varying from vendor to vendor. This makes it tricky to compare them.

Taking the manufacturers’ stated prices on their respective websites, the Phrozen Sonic Mini goes for approximately ~$240, whereas the Elegoo Mars, according to Elegoo, should set you back $369. Which is frankly laughable. At the time of publishing this article, that big online-only retailer – you know the one – has the Mars for just a handful more than the Sonic Mini at ~$250.

The Mars Pro is not listed, and is, seemingly, seldom available. Whenever we do see one for sale, it runs close to $299, but finding one is practically a dark art these days.

In terms of pure numbers, the Sonic Mini takes it. But again, this is only as of the time of our publishing this article. Prices change, shop around.

We’ll preface this verdict of sorts with the truth that, really, all three of these machines are fantastic budget MSLA 3D printers. Any dollar dropped on them is not wasted, because they all get our recommendation. But, our nod goes to the Phrozen Sonic Mini.

Weighing all of the above, there are some unavoidable conclusions to be made. The Elegoo Mars and Elegoo Mars Pro have it for print resolution (though you’d struggle to notice the difference between them all), print volume, and durability with their metal resin vats. The Mars Pro has the additional benefit of an air filtration unit.

All run ChiTu firmware and use ChiTuBox for slicing, so the experience of printing with them all is virtually identical. The Sonic Mini and Mars Pro handle files faster, but the Sonic Mini can print much, much, faster (it really does need to be seen to be believed). Of all the differences between the three printers, this is the one trait that has the most impact on their abilities.

And, at the time of publishing, the Phrozen Sonic Mini is the cheapest of the three. Ipso facto, the Sonic Mini wins.