Xiaomi Book S 12.4 review

Long a mainstay of the mid-priced Android market, Xiaomi has now turned its hand to 2-in-1 laptops, with its Xiaomi Book S 12.4 offering value and versatility in equal measure.  

It’s an ARM-based Windows 11 PC laptop that, thanks to its 12.4-inch LCD touchscreen, also doubles as a highly portable tablet.

But with rivals such as the Surface Pro 8 and Huawei MateBook E also playing the hybrid game, is its £650 price tag, Snapdragon 8cx Gen 2 chipset and 8GB of RAM enough to make it stand out?

Design & Build 

• Simple design 
• Windows Hello but no fingerprint sensor 
• Only one (USB-C) port 

The Xiaomi Book S 12.4 sits somewhere in the middle of the beauty spectrum, featuring an uncluttered design that will sit discreetly on your desk without turning any heads. Built using a dark-grey aluminum-magnesium alloy, its inoffensive black chassis weighs a practical 720g and is only 8.95mm thick.  

While the device’s clean design probably won’t win any awards, the bezels surrounding the 12.35in touchscreen are relatively slim for its price range. There’s also the welcome matte finish that won’t pick up too many fingerprints or smudges, so it will look more than presentable in an office or professional setting. 

With a 12.35in screen and dimensions of nearly 300mm x 200mm, it can be a little too large to hold for long lengths of time. This is where the official keyboard comes in, which is sold separately for £129 and which also includes a rear cover, with a helpful built-in stand. Obviously, this addition turns a mid-range laptop-tablet into something a bit pricier, but the easily adjustable, and sturdy, stand did generally make my life easier. 

Simon Chandler / Foundry

As with many other 2-in-1 tablets in its bracket, the Book S’ design is capped off by a rear camera (more on that later) which certainly makes an otherwise blank canvas (apart from the Xiaomi logo) look more interesting.

There isn’t a fingerprint sensor anywhere on the device, but it does provide a 3.5mm earphone jack and a single USB-C port. There’s also a microSD card slot on the right-hand side of the tablet, enabling you to upgrade its 256GB of internal memory. 

Other than that, the Xiaomi Book S 12.4’s touchscreen is built with Corning Gorilla Glass 3, making it more durable than some of its rivals. However, it doesn’t feature an official IP rating, so be sure to take care of it around water in particular. 

Accessories

• Responsive keyboard add-on with large key spacing 
• Xiaomi Smart Pen makes drawing and note-taking easier 
• Both accessories sold separately 

While Xiaomi is advertising its Book S 12.4 as a 2-in-1 device, owners will be able to use it as such only if they purchase its official keyboard. As stated above, this is sold separately at £129, transforming a £650 device into one costing £729.  

To be fair, many 2-in-1 tablets are sold separately from their compatible keyboards (e.g. the Microsoft Surface Pro 8), so the Book S isn’t unusual but including it would be a draw for potential buyers. And for what it’s worth, its keyboard is a decent one. 

Imaginatively named the Xiaomi Book S 12.4 Keyboard, it features a conventional Windows layout, with the Start button among the Control and Alt keys at the bottom and the F keys at the top. There are no fancy extras but the trackpad below the keyboard does substitute for a mouse very well. 

Simon Chandler / Foundry

Fitting the keyboard to the tablet itself is frictionless, with the magnetic Pogo Pin connector satisfyingly powerful. Once you’ve attached it, you can then fit the rear cover which comes packaged with the keyboard, which is also magnetic and easy to apply. 

At first, I didn’t think the cover could be folded to stand the screen up. However, you need to give its bottom half a good pull, so that it fixes into a more stable folded position. Once you’ve done that, you then truly have a 2-in-1 on your hands, with the angle of the screen slightly adjustable via careful refolding of the cover. 

The keys of the keyboard offer a relatively large key width, at 1.3mm, as well as a height of 1.5mm. This makes typing easy and intuitive, while the trackpad is sensitive without being too sensitive. The only minor downside is that opening the ‘laptop’ once you have the keyboard and rear cover attached doesn’t feel quite as seamless as it would with an actual laptop. 

Moving to the Xiaomi Smart Pen, this is a rechargeable stylus that attaches magnetically to the left-hand side of the Book S. It’s here that it recharges, with a full recharge requiring only 18 minutes and a single minute of charging providing 20 minutes. Once fully charged, it can last close to eight hours. 

Simon Chandler / Foundry

With a 240Hz sampling rate and the ability to distinguish 4,096 levels of pressure, the pen is enjoyably smooth to use, with low latency. It pairs automatically with the tablet via Bluetooth when charged, and makes drawing or note-taking a fluid and articulate experience. Helping it in this regard is its palm rejection, which remained consistent throughout my time using the Book S. 

It’s also worth pointing out that the Smart Pen is light and ergonomic, so using it for prolonged sessions won’t be a strain. That said, the keyboard will add 317g to the tablet, taking it over a kilogram. This isn’t too heavy, but it does undermine the portability factor of the Book S on its own. 

As with the keyboard, the Xiaomi Smart Pen also needs to be purchased separately, at a cost of £89. Combined with the keyboard, this takes the price of the Book S up to £819. 

Screen & Speakers 

• Bright 12.35in LCD display 
• 60Hz refresh rate 
• Balanced dual speakers 

In a market where many 2-in-1 tablets boast an OLED display, the Xiaomi Book S 12.4 settles for a more inexpensive LCD touchscreen. It offers a resolution of 2560 x 1600 (WQHD) pixels, with a pixel per inch count of 244ppi and a 16:10 aspect ratio. It also provides a basic 60Hz refresh rate.  

In other words, the display’s specs aren’t great, especially when OLED panels with 120Hz refresh rates are now more or less de rigueur. Still, with a typical brightness of 500 nits, and with the ability to cover 100% of the DCI-P3 colour gamut, it will prove enough for most people. Videos are clear and vivid, while images are generally sharp with a wide dynamic range. 

Simon Chandler / Foundry

One thing you may not notice about the display at first is that it supports 10-point multi-touch, meaning it can recognise and process ten points of contact at the same time. This makes it useful in work-related situations where more precision and efficiency is required, with the ability to scroll with one hand and open/close windows with another really speeding up tasks. 

Sound is carried by dual speakers sited on the left and right of the device, providing stereo sound of decent quality for the price. Music obviously isn’t quite as full-bodied or rich as you’d hear from a more premium audio device, but it remains balanced enough, with the tablet easily able to support conference calls and the like. 

Specs & Performance 

• Qualcomm Snapdragon 8cx Gen 2 chipset
• Limited performance 
• Only a single RAM and internal storage configuration available 

Unsurprisingly for its price, the Book S registers middle-of-the-road performance in comparison to its peers. Equipped with a Qualcomm Snapdragon 8cx Gen 2 (7nm) processor, it can’t quite keep up with Intel-based devices, yet it will be fast enough for most purposes. 

This is helped by its use of a Qualcomm Kryo 495 octa-core CPU, as well as 8GB of LPDDR4X RAM. However, there are no models of the device available with either more RAM or more than the 256GB of internal memory, so users shouldn’t set their expectations too high.

That said, performance is good in the round. Everyday tasks such as web browsing, word processing and multitasking are all managed without noticeable issues. Windows open quickly and apps load with few or no delays, while users can also run multiple windows without putting too much undue strain on the tablet. 

Simon Chandler / Foundry

In terms of more intensive tasks, the Book S doesn’t come off as well as more expensive 2-in-1 devices such as the Surface Pro 8 or Samsung Galaxy Book Pro 360. More demanding games tend to give it a little too much to digest at once, while it falls below the minimum requirement of many recent titles (e.g. I tried and failed to download and run the Forza Horizon 4 demo).

Likewise, certain professional editing apps will likely also drag performance down further, with obvious slowdown and lag. After all, there’s no discrete graphics card here to handle that stuff.

Other specs worth mentioning include support for Wi-Fi 5 and Bluetooth 5.1. These complete the picture of a 2-in-1 tablet that can do most things well, but without truly excelling in any particular area. 

This is also supported by its benchmarks, which reveal the Book S 12.4 surpassing cheaper models such as the Surface Go 3 but lagging behind slightly more expensive rivals such as the Huawei MateBook E and the Surface Pro 8.

Cameras

• 13Mp rear
• 5Mp front
• Windows Hello

The rear camera on the tablet is a decent 13Mp although photos taken using it are variable in quality. In particular, images captured in good natural light turn out quite well, without being spectacular, whereas anything with too much or too little light taxes the device’s software just too much to be useful.  

On the other hand, the Camera app can be used to capture the content of whiteboards and scan documents (and barcodes), so it performs better as a multi-purpose image tool than as a serious camera. The same goes for the 5Mp front-facing camera, which won’t really provide you with flattering selfies, but will at least be useful for conference calls and video-chatting with friends and family. 

Another interesting feature offered by the front of the device is a Windows Hello face unlock. It’s certainly not quite as effective or reliable as Apple’s Face ID, but if you’re in decent light and not too far away, it usually does a good job of saving you the bother of entering your PIN a thousand times. 

Battery Life & Charging 

• 42Wh battery 
• Underwhelming battery life 
• Decent 65W charging via USB-C 

With a battery weighing in at 38.08Wh, Xiaomi promises users that the Book S 12.4 will keep going for around 13.4 hours. This depends entirely on how you use it though, with the addition of the keyboard and the Xiaomi Smart Pen usually leaving you with significantly less staying power than 13 hours. 

The lack of stamina of the Book S’ battery is also borne out if you use it regularly as a media device, specifically for watching TV and films. For example, binge-watching several episodes of your favourite Netflix series can result in the device running out of steam within around half of the time advertised by Xiaomi.

Simon Chandler / Foundry

This is not great, particularly when watching video is one of the most common uses for a tablet. In our usual video loop battery test at 120 nits brightness, the Book S 12.4 lasted a middle of the road eight hours and 37 minutes.

While the battery itself is somewhat disappointing, Xiaomi’s 65W GaN charger goes some way towards compensating for its longevity issues. It can take you from almost flat to 50% in about 40 minutes, while a full charge arrives in just over an hour and a half. This is pretty impressive, although you will have to remember that, if you plan to work a full day with the device, take the charger with you. 

Software & Apps

• Windows 11 in S Mode 
• Streamlined UX without bloatware or clutter 

Running on Windows 11 out of the box, the Xiaomi Book S 12.4 uses Microsoft’s OS in S Mode by default. This is a safe mode that increases the device’s overall security, largely by erecting barriers against the downloading of unauthorised or unvetted apps.

For some people it will come as a useful addition, although more specialised users may prefer to deactivate it, freeing them up to install more niche applications that don’t come directly from the Microsoft Store. 

More generally, the Book S’ implementation of Windows 11 is smooth and simple, with an absence of bloatware or unnecessary apps. In fact, a scroll through the applications pre-installed on the device reveals that Xiaomi has opted not to add anything extra (unlike its Android phones), so users will pretty much receive the stock Windows experience. 

Simon Chandler / Foundry

Windows 11 remains an inviting interface, with an intuitive layout that’s easy to navigate. The OS has been optimised for tablets in various ways, with the inclusion of the Start menu (and accompanying icons) in the middle-bottom taskbar being the most obvious difference from previous iterations. Again, the Book S handles all of this well, with the device loading apps and windows quickly. 

One slight disappointment, however, is that the OS doesn’t make any obvious use for the Xiaomi Smart Pen, at least not by default. You can obviously use it as a glorified finger, as well as with the stock Word and Paint apps, but more specific uses will have to come with the downloading of third-party apps. 

This quibble aside, software is ultimately one of the device’s strongpoints, with its Qualcomm Snapdragon 8cx Gen processor enabling it to offer a frictionless experience. Xiaomi hasn’t made it clear for how long it will receive updates though, so don’t expect it to be better supported in this respect than Microsoft’s Surface devices, for instance. 

Price & Availability

On its own, the Xiaomi Book S 12.4 will cost £649.99/€699/$750. This would qualify it as a mid-range 2-in-1 tablet/laptop, yet if users want it to function as such, they’ll have to spend £129 more for its keyboard and £89 more for the Xiaomi Smart Pen.  

In total, this will push the cost up to £819, making the Book S £450 more expensive than the base model of the Microsoft Surface Go 3, and only £181 cheaper than the Huawei MateBook E, which comes with its Smart Magnetic Keyboard and boasts largely better specs. 

There are no alternate versions of the Book S with more RAM or internal memory, meaning 8GB of RAM and 256GB of storage are your only options. It can currently be purchased through the official Xiaomi website, with support from third-party retailers being minimal at the moment.

Check our chart of the best tablets and 2-in-1 laptops.

Simon Chandler / Foundry

Verdict

The Xiaomi Book S 12.4 is a good option for anyone seeking a 2-in-1 tablet that doesn’t cost too much but still offers a wide gamut of functionality. It does nearly everything its more expensive rivals such as the Surface Pro 8 and Huawei MateBook E do, while also saving the user at least a couple of hundred pounds (or euros), depending on which add-ons they purchase. 

Despite using an LCD panel and missing a faster refresh rate, its 12.35in display is big and bright enough to provide an enjoyable viewing experience, while being more than adequate for work purposes. Its performance is also more than sufficient for most day-to-day purposes but nothing too demanding. 

It’s more of a mixed bag with battery life, because while the Book S recharges quickly, it can lose power with almost as much speed. Using it in tandem with the keyboard and Xiaomi Smart Pen can sap its juices easily while using it as a work device will necessitate having it plugged in (unless you want it to conk out on you by the afternoon). 

These criticisms aside, the Book S’ implementation of Windows 11 is laudably clean, while the device has enough strong points to recommend it on the whole. It may cost slightly more than its advertised price tag of £649 if you want to fully actualise its 2-in-1 status, but it still undercuts a handful of its nearest counterparts.

Specs

• Windows 11 in  S mode 
• 12.35in 2560 x 1600 LCD display, 60Hz, WQHD+ 
• Qualcomm Snapdragon 8cx Gen 2 processor 
• Qualcomm Kryo 495, Octa-core CPU, up to 2.84GHz 
• Qualcomm Adreno 680 GPU 
• 8GB RAM 
• 256GB SSD 
• microSD slot 
• 13Mp rear camera 
• 5Mp front-facing camera 
• Dual speakers 
• Wi-Fi 5 
• Bluetooth 5.1 
• Up to 13.4 hours of battery life (quoted) 
• 65w charging (charger sold separately) 
• 720g (tablet only)