Jsaux ModCase for Steam Deck review: “A smart set of handheld armor”

Jsaux ModCase next to Steam Deck on woodgrain table
(Image: © Future / Phil Hayton)

GamesRadar+ Verdict

Valve’s handheld might come with its own case, but the Jsaux ModCase adds modular functionality and a durable hard shell to the portable without adding much bulk.


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    Full cover protection

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    Modular system for accessories

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    Built-in kickstand


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    Adds extra weight

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    Only comes in black

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I’m going to upset a few of you by saying this, but I prefer my handhelds and smartphones to be naked. Therefore, I wasn’t initially into the idea of using the Jsaux ModCase for Steam Deck full time, as I was convinced the extra layer would upset my brain. Yet, after using the case for chunks at a time, I’m happy to report that it didn’t give me the ick, and the shell’s modular abilities actually played a part in winning me over.

When recommending Steam Deck accessories to friends, I normally skip over cases entirely. I mean, the new Steam Deck OLED comes with its own that transforms into a slimline zip-up shell, so why would you want to go and splash out on a third party alternative? Well, the Jsaux ModCase provides a few compelling reasons, and most of them relate to pulling off ridiculous gaming handheld ensembles when out and about. 

At $29.99 / £29.99, the Jsaux ModCase isn’t the cheapest around. However, it’s not actually much more expensive than many other options out there, including no name shells that lack modular pizazz. So, while it’s more than I’d typically like to pay for a case, I can’t give it too much shtick considering its abilities and level of protection it offers.


Jsaux ModCase front and back shell on table next to accessory strap

(Image credit: Future / Phil Hayton)

Using a blend of hard plastic, flexible rubber, and a sprinkle of metal for the back stand, the Jsaux ModCase is designed to envelop your entire Steam Deck. I keep arguing with myself whether it's technically a shell or a case, but I think it serves as both thanks to its detachable front cover that acts like a shield. 

Keep in mind what I said before about not liking handheld shells, but I’m not the biggest fan of the way the ModCase slides onto the Steam Deck. “Slides” perhaps isn’t the right term, as getting it on involves pushing the corners into the bottom, then carefully moving the triggers into place so that it all snaps together. If done correctly, it’s not going to pose any risk to the portable PC, so don’t let my aversion to these kinds of accessories put you off. Once it’s actually on, there’s no risk of it shifting or releasing itself during use, meaning the tight fit fills the brief. 

That said, being a full cover shell is only a part time job for the ModCase, as it also moonlights as a modular system for holding other accessories. It achieves this by including what’s best described as a rubber watch strap that slides onto grooves at the back, allowing for anything roughly the same size as a smartphone to be strapped on like a backpack.

It’s admittedly a simplistic system, and the rubber strap doesn’t feel particularly durable, but it does get the job done. There’s a thoughtful soft pad that will protect anything you do strap to it from being scratched by the rear of the case, whether you’re using a battery bank or something with a casing susceptible to scratches. 


Back view of Jsaux ModCase for Steam Deck

(Image credit: Future / Phil Hayton)

Naturally, the ‘mod’ part of the ModCase is the main draw, and we’ll get to how it works in practice. However, I want to touch on its qualities as a case first, as it serves as a smart set of handheld armor. That push-fit plastic cover almost makes it look like the Steam Deck is using ‘harden’ like a Pokémon, providing separate divots for the analogue sticks. Cut outs for the back buttons and triggers also mean you won’t have to deal with any covers affecting tactility, while the top volume and power buttons are protected from dust and other nasty bits.

Alright, let’s talk about the weird watch strap at the back. Technically, it’s not the only thing that can attach to the ModCase, as Jsaux has a Steam Deck dock, namely the 11-in-1 Docking Station, that will slide into the same place. There’s also a version with a trio of adhesive pads, providing you with even more ways to fuse anything you want to attach to the handheld. I don’t have that particular model to hand, so I can’t attest to how sticky the pads are. Still, if you’ve got something slimmer to attach, like an SSD enclosure, it’s bound to come in handy.


With that in mind, I used just the watch strap during testing, and I have no complaints with how it performs. I’d say that for an accessory to stay put without wobbling, you’d need to use something that’s as big as a 3.5inch external hard drive, which became apparent when I tried to slide an SSD caddy in there. Of course, it also has its upper size limits, as it won’t remotely stretch wide enough to hold chonkier battery banks like the Baseus Blade that I use on a daily basis.

I’d say that to get the most out of the ModCase, you need to be the type of player that throws a bunch of accessories and the Steam Deck into a rucksack regularly to set off somewhere. I sort of fall into that category, as I’m a nightmare when it comes to carefully organising things for a trip into cases and compartments. On this front, Jsuax’s shell served me pretty well, protecting the Deck from the dangers of my other backpack things while clutching onto any add-ons I might need at that moment. 

One gripe I do have with the ModCase is the weight it adds to the handheld. I mean, extra heft is a given, especially if you’ve got stuff attached. But still, it makes what is already a burly handheld feel like a tank, and I mean that in both a positive and negative light. If I somehow manage to drop it, even though its textured grip is quite effective, I’ll come back and thank it for giving my hands a workout. For now, it’s something I’m going to grumble about when mentally comparing it to the lighter experience of playing on a naked Deck.

Should you buy the Jsuax ModCase for Steam Deck? 

Jsaux ModCase next to Steam Deck with start-up animation

(Image credit: Future / Phil Hayton)

If you’re looking for a durable shell that offers full body protection for Valve’s portable powerhouse, the Jsaux ModCase for Steam Deck is a solid pick. The fact it offers up additional modular functionality sweetens the deal, and is bound to be a godsend for any player who finds themselves regularly juggling connected add-ons while out and about.

I’d prefer if it came in more interesting colors, and the way it tight fits to the handheld still gives me the fear. Nevertheless, if you’re craving coverage different from the solution included with Valve’s handheld, or you bought the portable second hand and don’t have any protection, the Jsaux ModCase is worth investing in.

How I tested the Jsaux ModCase for Steam Deck

For several months, I used the Jsaux ModCase to protect my Steam Deck using daily use. To put its level of protection and coverage to the test, I relied on the accessory to prevent scratches and accidental damage both at home and outside, with my backpack serving as the only other barrier between the handheld and other elements. I also regularly used the modular back clip to hold connected add-ons like docking stations, hard drives, and even my smartphone, paying close attention to ensure anything attached stays secure during longer sessions.

For more information on how we test accessories for console and PC, swing by our full GamesRadar+ Hardware policy.

Need more add-ons for the Valve's handheld? Check out the best Steam Deck headset and best gaming keyboard for peripherals that will pair with the portable. Alternatively, take a peek at the best gaming laptops if you'd prefer an all in one machine you can take on the go.

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Phil Hayton
Hardware Editor

I’ve been messing around with PCs, video game consoles, and tech since before I could speak. Don’t get me wrong, I kickstarted my relationship with technology by jamming a Hot Wheels double-decker bus into my parent’s VCR, but we all have to start somewhere. I even somehow managed to become a walking, talking buyer’s guide at my teenage supermarket job, which helped me accept my career fate. So, rather than try to realise my musician dreams, or see out my University degree, I started running my own retro pop culture site and writing about video games and tech for the likes of TechRadar, The Daily Star, and the BBC before eventually ending up with a job covering graphics card shenanigans at PCGamesN. Now, I’m your friendly neighbourhood Hardware Editor at GamesRadar, and it’s my job to make sure you can kick butt in all your favourite games using the best gaming hardware, whether you’re a sucker for handhelds like the Steam Deck and Nintendo Switch or a hardcore gaming PC enthusiast.