I’m someone who loves a good mobile controller. I travel fairly frequently as I’m in a long-distance relationship, so despite wanting to play games when I can, I find myself away from my consoles more often than not. My biggest issue is finding a controller that allows me to chip away at that mountain of games while being comfortable in the process, and that’s where the GameSir X4 Aileron comes in.
I’ve been a big fan of the Backbone controller ever since its release. It felt like it was designed specifically for my situation, and for a lot of people, it’s the best mobile controller for that reason. However, it’s hard to deny that it lacks certain appealing features that other big hitters have taken a swing at. GameSir’s G8 Galileo is more ergonomic and has two back buttons, which helped it earn our title of the “backbone breaker.”
The GameSir X4 Aileron takes that same swing in a more portable form factor and produces a controller that says “Anything you can do, I can do better”. It does so at $99.99/£99.99, which puts it exactly even with Backbone’s signature controller.
Design
My biggest issue with the Backbone One controller and most mobile controllers I have tested is how small they feel in hand, leading me to give up on gaming sessions much quicker than I would if I were playing on a console. However, I’ve not found that to be the case for the GameSir X4 Aileron. This is in large part due to the more substantial size given to the grips which are formed to fit perfectly into the palm of your hand. Not only that but they feature a textured plastic coating meaning that you’re unlikely to have the controller slip out of your hands.
When it comes to mobile controllers you will often struggle to find full-sized, or close to full-size, thumbsticks. Generally, you’ll find something half the size, like the Backbone’s tiny nubs. So you don’t have to be locked into only one stick size, GameSir provides you with three different options in Alieron’s box. It comes default with a smaller-than-regular Xbox-style thumbstick but in its very handy travel case, you’ll also find the options for full-sized Xbox-style sticks as well as the Backbone-style ones. I tested all three and found the full-size ones to be the most comfortable and the most appealing for long gaming sessions. Regardless of which thumbstick style you choose, you’ll be using GameSir’s Hall Effect sticks when gaming, something which you’d expect to find on the best PC controllers, so it’s nice to have here.
GameSir has gone for the seemingly industry-standard layout of offset thumbsticks. I’m not always a fan of this as it can often lead to cramps and a sore thumb on a smaller controller, especially in games that require heavy use of the camera controls.
Features
You’ll find Xbox layout face buttons which can be customized and swapped very easily to the Switch layout thanks to their magnetic attachment. Regardless of which layout you choose, you’ll feel a very satisfying click from them due to them being tactile micro-switch buttons. This goes for the D-pad and the bumpers too. Additionally, at the rear of the controller, you’ll feel two mappable buttons perfectly placed where your middle fingers should lie when using the controller.
The GameSir X4 Aileron bucks the trend of having a spine that holds both halves of the controller together. Instead, GameSir has opted for a more Nintendo Switch Joy-Con-style design. Two halves magnetically clip together for storage and charging, which can be done so via the USB-C port at the base of the left controller, and pull apart for you to attach to your phone.
Attaching is very simple, you place the phone inside the green GameSir clips which turns on the controller and connects it via Bluetooth to start your gaming session. However, this is not compatible with phone cases and certain handsets will either be too large or too thin - I used a Samsung Galaxy S21 and found the controller to feel flimsy and very loose despite the added rubber padding that GameSir provides. Despite being Bluetooth, I was unable to connect the device to my iPhone 14 Pro Max and have it register as a game device. In fairness, it is advertised as an Android-only device so that is expected, but it is strange that there isn’t iPhone compatibility at all.
Finally, it wouldn’t be a nifty piece of gaming tech if it didn’t feature some form of RGB. As someone who isn’t the biggest fan of it, I wasn’t offended by it here. Each thumbstick is surrounded by a ring of RGB which actually adds a nice finish to the controller.
Performance
As previously mentioned, the GameSir X4 Aileron features two rear mappable buttons which is a feature that I’ve been wanting for a long time on a mobile controller - you find them on all the best Xbox Series X controllers, and even on the best PS5 controllers, so why not for mobile gaming? This was probably my favorite feature of the controller. It really brought together my mobile gaming sessions, making them more comfortable and more like a console experience. Despite sitting almost perfectly where your middle finger sits when holding the controller, I did find them to be a little small, and in high-stress situations in FPS games I did struggle to find them occasionally, this is despite the slight texturing they have.
I loved the Backbone One but it’s hard to deny it now lacks key features that you should find in the best controllers on the market.
The buttons themselves are mappable via the on-board ‘M’ button and are very straightforward. This feature I used extensively to change up my tactics on the fly in games to allow me to have the most comfortable experience. While playing Avatar: Frontiers of Pandora via Amazon Luna, I would assign each back button the corresponding Thumbstick click input, so I had my sprint and melee controls within reach at all times - clicking thumbsticks in is something I find very difficult on mobile controllers, so this was the solution.
Hall Effect, full-sized thumbsticks on a mobile controller are a great addition and really make this pad stand out compared to its biggest rivals including the Backbone One. I often find hall sticks very sensitive and the same went for here, but that was very easy to tweak in-game settings or the GameSir app which allowed me to tweak their deadzones. The biggest downside for me was the offset design. I'm someone with slightly larger hands and I found it to be uncomfortable for long gaming sessions, especially as the right stick is placed so low on the right pad that my thumb would hurt after a while. I understand why they would target that design, especially when it's seemingly industry standard, and with the device aimed at Xbox Cloud Gaming, you want a layout that is familiar for those players. It just didn’t work for me.
Alongside cramp, I found because of where it was placed my palm would often nudge the stick when trying to click face buttons. It’s a small annoyance but one that did cost me a couple of times in FPS games such as Call of Duty Mobile as my camera was not pointing where I wanted it to be.
Going into testing the GameSir X4 Aileron, my biggest concern was latency. This controller does not connect to your phone via USB-C and instead, it’s all done via Bluetooth. Thankfully, it was seemingly indistinguishable 99% of the time for both native and cloud gaming. My inputs were received perfectly and in very quick fashion, so much so I couldn’t measure any input lag at all. Aside from one situation when playing The Crew MotorFest via Amazon Luna, I found that controlling the car to have a slight delay but I believe this to be internet/server issues as I went and tried it on my Backbone One controller straight after and I experienced the same lag there.
I’m someone who absolutely adores the Backbone controller, it was a revelation when I purchased it, and it allowed me to take my gaming on the go while not compromising on the experience, I thought it couldn’t get better than that. However, it’s clear that after spending time with the GameSir X4 Aileron, it does get better and mobile controllers are going from strength to strength.
Should you buy the GameSir X4 Aileron?
As I said, I loved the Backbone One but it’s hard to deny it now lacks key features that you should find in the best controllers on the market. All of those key features can be found on the GameSir X4 Aileron, making me ask myself if I’ll ever go back to the Backbone.
My biggest issue with that, however, is that the GameSir X4 Aileron has no support for the iPhone despite it being a Bluetooth connection - perhaps this will change in the future but it doesn’t look like it'll come anytime soon. If you’re an Android user and are looking for a change or a larger controller at the same price as a Backbone then I’d recommend it. If you have slightly smaller hands than normal and don’t mind the offset sticks then I’d suggest you purchase it.
However, if you want the best possible mobile controller that gives you the closest experience to playing on a console as one can, you might want to check out the GameSir G8 Galileo, or the Razer Kishi Ultra. Either way, the GameSir X4 Aileron is one of the best mobile gaming experiences on the market and is worth your money.
How we tested the GameSir X4 Aileron
I tested the GameSir X4 Aileron for roughly a month and used it as my primary way to play games for a week and a half of that time while using a Samsung Galaxy S21. I played through the first 12 hours of Avatar: Frontiers of Pandora via Amazon Luna exclusively using the GameSir X4 Aileron while also playing Forza Horizon 5 for approximately 5 hours via Xbox Cloud Gaming. Alongside cloud gaming, I extensively played Call of Duty Mobile natively on the phone.
Throughout my testing, I often compared it directly to the Backbone One controller due to it being one of the market leaders.
For more on how we test the latest gaming gear, check out our Hardware Policy.
To get more platform-specific, check out the best PS5 controllers, the best Xbox Series X controllers, and the best Nintendo Switch controllers.
