Review: the Cosmo Communicator

It’s 2021, and it’s time to upgrade your smartphone. Maybe it’s getting slow, it might be damaged, or your device’s OEM refuses to update your version of Android. Whatever the reason, you set your budget and full of hope and starry-eyed about all the possibilities, you go to your preferred electronics store (or carrier, if you’re American) – and as you scroll through the possible phones, your hopes are shattered and your heart sinks in your shoes. Your choices are between an endless array of black slabs, and while you can technically choose between Android and iOS, you will have most likely made that specific choice ages ago, and switching platforms is hard.

Slightly dramatised, sure, but the reality of smartphones today is that all of them look and feel the same. The difference between mid range and high end have shrunk over the years, and while there are still small differences here and there, the general experience is going to be the same from device to device. Even if you skip a few years of upgrades, the jump in performance to the latest and greatest processor isn’t going to make that much of a difference in your day to day use. While you can technically opt for one of the new folding phones, the reality is that they still suffer from early adopter problems, and their prices are far beyond what most of us would want to pay for a smartphone.

With all phones looking the same, it’s hard to find a company willing to stand out in a crowd of black rectangles. One of the victims of this race to the rectangle is the smartphone keyboard – whether it’s BlackBerry or Android phones with keyboards, they’re basically no longer being made, and if you’re simply not a fan of typing on featureless glass, you’re pretty much out of luck.

Except, not really. There are a few companies left still making smartphones with keyboards, and the British company Planet Computers is one of them. This British company does not just focus on building Android smartphones with keyboards – they take the concept a step further and gun for the iconic Psion devices from the ’90s. The company’s chief designer, Martin Riddiford, worked at Psion in the ’90s and aided in the design of the Psion Series 5’s keyboard, and that design has formed the basis for the company’s first two devices: the Gemini PDA and the Cosmo Communicator.

After seeing my sorrowful lament of the Nokia N900, the company contacted me and asked me if I wanted to review their Cosmo Communicator Android smartphone. I obviously didn’t hesitate to say yes, and after a few weeks of delay due to our first child being born, I can finally give you my thoughts and insights on this device that fills a unique niche in the current mobile landscape.

Keyboard and hinge

The Cosmo Communicator is unlike any other Android device on the market today. As to be expected due to its pedigree, the device resembles a Psion Series 5, or perhaps a Nokia Communicator if you’re more familiar with that line of devices. When closed, the device is thicker and heftier than most other smartphones, but there’s a valid reason for that: open it up, and inside you’ll find a full QWERTY keyboard with real keys. When opened, it looks more like a small laptop than a smartphone.

Full disclosure: Slimbook sent us the Executive as a loan, and it will be returned to them. They did not read this review before publication, and placed zero restrictions on anything I could write about.

I want to dive straight into that keyboard, since it’s by far the device’s most defining feature. First of all, it’s smaller than a regular keyboard, obviously, so it definitely takes a little time to get used to. I have small hands and tiny fingers, so for me, it wasn’t that hard to get used to the size of the keyboard. The layout of the keys feels natural, and for me, there are no cases where I would’ve opted for keys in different positions. With such a cramped space, you’ll always have to make compromises and hard choices, but I think the Planet team has made all the right choices. The layout will take some getting used to, but that’s to be expected with any new keyboard, especially one in such an exotic form factor.

I’m slightly less happy about the actual typing experience, though. Granted, I am a very light typist who applies relatively little force to each key press, but I found that my key presses would often not register unless I applied what I would consider too much force. This problem increases the farther away from the home row I am, and it’s downright annoying. Getting used to a new keyboard layout and smaller keys is one thing – unless you have truly gigantic hands, it won’t take you more than a few days – but having to change how hard you press down on a key is very, very hard to learn. However, as said, if you apply more force for each key press than I do, this might not be much of an issue at all for you.

You might wonder if you can use the keyboard when thumb-typing. My hands are definitely too small for thumb-typing, as reaching the centre-most keys requires an uncomfortable amount of stretching and grip adjustments. Again, though, my hands are small, and if you have more average-sized hands, you might be able to thumb-type just fine.

The keyboard is backlit, and comes in a variety of keyboard layouts to choose from upon purchase. Using the Fn key, you can also control things like volume, brightness, airplane mode, and other Android-specific features, and Planet was smart enough to include full inverted-T arrow keys. Aside from the cramped size, it comes very close to offering all the functionality of a regular keyboard, and while my personal typing style doesn’t mesh well with it, the Planet team has done a great job given the constraints they were working in.

Moving on from the keyboard, the second aspect of the Cosmo that stands out is its hinge. Anybody who has ever handled a Psion Series device from the ’90s will recognise the look and feel of the hinge right away, and the design has held up incredibly well. It’s solid, feels satisfying, and props up the device a tiny bit when opened. The use of more metals instead of just plastic like on the old Psion models gives it a much sturdier feel, too.

I do wish the hinge had more positions than just fully open, though. The angle of the display is fine when putting the phone down on a table, but since the hinge wants to be either fully closed or fully open, there’s no positions in between that might be more suited for a wider array of situations. For instance, if you want to lie down on the couch or in bed late at night, there’s really no way to position the device for optimal video viewing. This is a giant missed opportunity.

The rest of the hardware

The remainder of the device is a fairly standard mid-range Android smartphone. It’s powered by a MediaTek Helio P70, an SoC released in 2018 with 4 Cortex-A73 cores at 2.1 GHz and 4 Cortex-A53 cores at 2.0 Ghz. Packed with a solid 6GB of RAM, an ARM Mali-G72 MP3 GPU running at 900MHz, and 128GB of storage, the phone never feels slow or out of breath. I know a lot of people are hyperfocused on making sure they get the latest and greatest SoC, but the reality is that by now, virtually any SoC from the last few years in the mid-range and up is more than capable enough to run Android, and the P70 is no exception.

The main display of the phone is a 5.99″ 2160×1080 16:9 LCD which looks just fine. It’s definitely not in the same category as what you’d find on top of the line Android phones, but it’s more than good enough. The main display has two giant black pillars next to it, but this never bothered me. The secondary display – which sits on the lid on the outside – is a 1.91″ OLED touchscreen. It allows you to perform basic smartphone tasks while the device is closed, and shows things like notifications, system toggles, and more. You can also make calls from this screen, use a pincode to log in, and so on.

The secondary display – Cosmo calls it the cover display – ensures you don’t have to open the phone to make calls or perform basic tasks, which makes it a more than worthwhile addition. The software powering the display is managed and updated independently from Android itself, so it can also be used in other operating systems such as Linux. The Android installation comes with an app to manage and update the cover display, and during my time with the phone I received one or two updates.

Below the cover display you’ll find a fingerprint reader which also acts as a button for things like accepting and ending phone calls. I wish the fingerprint reader was placed in a slightly more convenient location, since reaching around the back to use it when the device is opened is not always easy, but it’s not a huge deal. It also comes with a few notification lights that you can configure yourself from within Android.

As far as ports and connectivity goes, the Cosmo comes as fully packed as can be. It pretty much supports every band under the sun, and obviously comes with WiFi (a/b/g/n/ac) and Bluetooth (5.0), GPS, NFC, and the usual complement of sensors. Thankfully, it comes with stereo speakers, which I think is a must for a device in this form factor, a regular headphone jack, and not one, but two USB-C ports. Sadly, when I tried to connect the device to an external monitor with my own USB-C-to-DP or USB-C-to-HDMI cables, it did not work. It turns out you need to buy Cosmo’s own specific dongle to enable external display functionality, which is a bit of a nuisance. Things like external mice and keyboard work just fine, though. Lastly, there’s a button on the side to open up the voice assistant, and it has support for dual SIM, e-SIM, and microSD cards.

I’m not exactly a camera expert, so I honestly don’t know what to say about the two cameras on the device. It has a 24MP main camera, and a 5MP selfie camera on the inside of the device, and photos taken with the main camera look fine to my untrained eyes. If photography plays a major role in your purchasing decision, I’d highly suggest finding a review from someone with far, far more knowledge on this subject than I have.

As a whole, I like the hardware of the Cosmo. There’s always going to be compromises with a device in this form factor, since it’s impossible to design something within such constraints that is perfectly suited for every possible typing style, hand size, and so on. I think Cosmo managed to strike a pretty good balance here, though, but I want to stress that the Cosmo is not merely a smartphone. Its form factor and design are closer to a small laptop than a traditional smartphone, and many of the compromises you’ll run into stem from this design decision. If you are more interested in a smartphone-first kind of design, you should probably take a look at Planet’s upcoming Astro Slide.


With interesting hardware comes interesting software, and here, the Cosmo does not disappoint. First and foremost, the Cosmo is an Android device, and anyone who is familiar with Android will feel right at home on the Cosmo. It’s a relatively stock installation of Google’s mobile operating system, but it does come with some applications developed (or forked from open source applications) by Cosmo. For instance, it comes with a modified version of K-9 Mail, an open source email application. Another example is a small application to customise the notification light patterns for incoming notifications, and the aforementioned application to manage the cover display. None of them are intrusive, but since they are set as system applications, they cannot be easily uninstalled either. My suggestion would to mark these as regular applications, so users can more easily uninstall them, without having to resort to adb.

Other than the few additional applications, this is a pretty much stock installation of Android, but it does come with one massive downside that I simply cannot ignore: it’s Android 9.0. Android 9 was released on 6 August 2018, making it almost three years old at this point, and for a device that isn’t cheap by any stretch of the imagination, Cosmo needs to do better. The company told me that their next device, the Astro Slide, will come with Android 11, and much of that work can be replicated on the Cosmo, meaning Android 11 for the Cosmo should be released later this year. However, for now, you’re stuck with a three year old version of Android.

Android is well-suited for the Cosmo’s form factor, and multitasking with two applications side-by-side with the device open is a really nice experience. It comes very close to a regular laptop, with only the lack of an integrated pointing device being a real issue. Of course, an external USB or Bluetooth mouse easily solves the lack of a mouse, at which point it really feels like using a tiny laptop. I did wonder if a point device can be added somewhere to the design of the device, but honestly, I feel like any possible solution would be far too compromised to be useful.

Luckily for us OSNews readers, though, the Cosmo supports more than just Android. One of the major and most interesting alternatives to Android is traditional Linux. The open source community maintains a port of Debian Buster (10.9) that you install alongside Android, and which uses the Android Linux kernel. My unit came with this version of Buster preinstalled, booting straight into KDE. It’s remarkable to see a full desktop Linux distribution run on such a small device, but running at 2× scaling, the user interface elements are big enough without taking up too much screen real estate. In fact, it’s entirely usable, and I had a total blast playing around with it.

Since this is plain old Debian, pretty much anything in the Debian repositories will work, since ARM is a supported architecture. You can set up your own desktop the same way you would set up any KDE installation on a regular PC or laptop, and other than the smaller display, there’s really nothing special or extraordinary about it.

The official Linux image for Cosmo also makes some special affordances for the device. It comes with a phone and SMS application, so you can make phone calls and send text messages right from within Linux. You can also set up the cover display as an external touchpad, but while an interesting gimmick, I did not find this particularly useful. Version 4 of the Linux image also introduces better support for the shortcut keys to control various aspects of the hardware, like WiFi, Bluetooth, and cellular. Sadly, this version was released a few days before my fiancee and I had to go to the hospital to deliver our child, so I haven’t been able to test it quite yet. It requires a fresh installation due to a switchover from droid-hal-cosmopda-bin to lxc-android, and I do not feel comfortable performing such an installation on devices that aren’t mine.

Performance of the Linux image was great, and I did not notice any serious shortcomings. Of course, if you come in expecting the performance of a big gaming laptop you’re going to be disappointed, but if you have reasonable expectations, you won’t be disappointed. It’s too bad I couldn’t test the external display support, because that would be an absolutely ideal use case for this device, especially for people who work in a variety of locations.

One downside of the Linux image is that it’s based on Debian Buster, which means some of the packages are going to feel a bit outdated because Buster favours stability over bleeding edge. The KDE version, for instance, is three years old, which is perfectly fine and working well, but you will miss out on more recent features and improvements. It would be great if other, more up-to-date distributions, such as Ubuntu or Manjaro, could be made to work on the Cosmo for those of us of a more adventurous nature.

Despite this shortcoming, the Comso’s Linux support is excellent, and it can easily serve as a small Linux laptop – assuming you bring a mouse with you, since it isn’t suited for touch input at all. The desktop Linux support is a major selling point for the Cosmo, and if it supported a more up-to-date distribution, I’d seriously consider this as its main operating system.

Are Android and desktop Linux not enough for you, or do you want something even more exotic? The Cosmo also supports both Sailfish OS and Ubuntu Touch. My unit came preinstalled not only with Android and desktop Linux, but also Ubuntu Touch. It runs perfectly well on the Cosmo, but Ubuntu Touch is clearly still in flux with pretty much no application support, and on top of that, it doesn’t seem very well-suited for the form factor of the Cosmo – it wants to be on generic glass slab phone, not on a tiny laptop. While it’s definitely cool to have access to Ubuntu Touch so you can keep track of its development, I found it more of a fun gimmick to boot into every now and then than a real alternative to the full Android experience or the desktop prowess of Linux.

In conclusion, the strength of the software on the Cosmo does not necessarily lie in any one of the operating systems specifically, but more in the fact that it’s so versatile and open to whatever you want to use. The Android experience is generic – that’s a good thing – and does exactly what you’d expect from Android on a smartphone, and desktop Linux with KDE is ‘just’ desktop Linux with KDE, albeit running on a pocketable mini-laptop without any compromises to what makes desktop Linux desktop Linux.

The area where the software sadly falls flat is that it’s outdated, which is especially cause for concern on the Android side. The Cosmo Communicator clearly tries to appeal to the more nerdy, more enthusiast segment of the market, and in those markets, Android 9 (or even 10) in 2021 is simply not a very strong showing. If they can get Android 11 for the Cosmo out soon that’d be great, but never buy something on the promise of future updates. Of course, if an older version of Android does not bother you, this entire point becomes moot.


The Cosmo Communicator with a US keyboard layout costs €789.95. That’s not cheap by any stretch of the imagination, especially when you compare it to other smartphones in that price range, but I feel like that’s not a fair comparison given what the Cosmo is trying to be. It’s not a smartphone – it’s a small pocketable laptop with smartphone functionality built-in. If that distinction matters to you, and you’re looking for that convergence between your smartphone and your laptop, there’s really not much on the market today to choose from. There’s the F(x)tec Pro1 X, but it has tiny rubber keys instead of the more traditional ‘full’ keys of the Cosmo, and costs €700 and is only in the pre-order phase at the moment.

Planet Computers is a small company in a sector dominated by a small number of heavyweights, and much like with the Blackbird Secure Desktop we reviewed earlier this year, custom, niche hardware simply comes at a price. If you’re debating between the Cosmo and a generic €800 Android slab, I’m pretty sure you were never going to opt for the Cosmo anyway. It offers a set of very unique features that few – if any – other devices can offer, and you’re either willing to pay for those, or not.

If you are, however, I think you’re going to end up with a device you’re going to like. It lives up to its promises, doesn’t drop any major balls other than the Android version, and enables use cases no other device on the market today can offer you. Using the Cosmo over the past few weeks, made me realise just how much of a pure OSNews bait this device really is. If there is one audience that can appreciate and enjoy the unique features the Cosmo offers, it’s the OSNews audience.


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