These portions also have a relatively sharp edge that cuts through the middle of the curve. I found this as comfortable to grip as many of the best Xbox controllers , and the angle these edges create allowed me to secure my fingers better, which in turn made the back buttons easier to use.
Connecting the X4 Aileron to my smartphone was quick and simple, although having to disconnect and reconnect by unclamping and re-clamping is a somewhat clunky process. The clamping mechanism of the X4 Aileron is secure, although it’s not the most elegant. It’s understandably tight, but this makes it hard to move it up and down when attaching and detaching a phone. I often found it best to slide my phone in and out rather than move the clamp by hand. It just about fit my phone in its case, although the lips of the clamp didn’t quite overhang the edges of my device, as they were supposed to.
Still, my phone stayed in place, although it was noticeably looser when attached without my case. Optional pads are included to remedy this, although these require sticking to the X4 Aileron, so this is a permanent solution rather than a removable one, which is a shame.
Customizations and tweaks can be made using the GameSir mobile app, but it’s disappointingly limited in scope. There’s no option to remap inputs, and while you can alter the deadzone for both the sticks and triggers, you can’t adjust their curve profile. There is a Hair Trigger mode, though, which is useful when rapid taps are called for.
The overall performance of the X4 Aileron is pretty good. The buttons are very snappy, especially the D-pad, which is very fast and easy to use, while the Hall effect joysticks and triggers are smooth and precise.
However, my major contention concerns the right stick, which I found hard to reach without sacrificing my grip. This is particularly problematic when using the right trigger at the same time, as you’ll be doing when playing shooters.
Battery life doesn’t seem particularly impressive either. After a couple of hours, each pad lost about 15% charge. However, the battery readouts in the GameSir app were a little erratic, flitting up and down in an instant, and changing quite drastically on occasion when reconnecting to my phone. Hopefully, this is something a firmware update can fix.
In terms of price, the X4 Aileron sits towards the higher end of the mobile controller sector, with many cheaper alternatives available. The Backbone One, which nominally is priced the same as the X4 Aileron, can often be found for less, and has the advantage of being compatible with iOS as well as Android systems. However, it’s cheaper than the Razer Kishi Ultra , but we do think that is among the best mobile controllers right now, so is deserving of its price tag.
Regardless, if you were to opt for the X4 Aileron, you won’t be disappointed, so long as you don’t need iOS support and can live with the placement of that right joystick.
GameSir X4 Aileron review: Price and availability
$99.99 / £99.99 / AU$169 Available in black only Expensive compared to rivals
The GameSir X4 Aileron costs $99.99 / £99.99 / AU$169 and is available now in one colorway (black). It comes with a carrying case, two extra sets of joystick caps (one of which is smaller), an extra D-pad hat, and optional rubber cushions that can be stuck onto each pad to fit thinner phones.
The X4 Aileron is priced towards the top end of the mobile controller market. However, it’s still cheaper than the Razer Kishi Ultra, which is one of the most expensive models around. That controller excels in virtually every aspect, though, and unlike the X4 Aileron, it’s compatible with iOS as well as Android devices, and can even handle tablets up to eight inches. It doesn’t have Hall effect sticks, though – only its triggers use this technology.
With the same list price as the X4 Aileron, the Backbone One is another close competitor. However, you can often find it for a lot less than this. We think this is another very capable mobile controller and is again compatible with both Android and iOS phones and tablets. However, it doesn’t use Hall effect technology.
GameSir X4 Aileron review: specs
Swipe to scroll horizontally
Price
$99.99 / £99.99 / AU$169
Dimensions
3.85 x 3.05 x 1.77in / 97.8 x 77.5 x 45mm (w/out phone), 3.85 x 9.3 x 1.77in / 97.8 x 235 x 45mm (w/ phone)
Weight
6.5oz / 186g
Connection type
Wireless (Bluetooth), wired (USB-C)
Compatibility
Android (phones)
Software
GameSir App (Android)
(Image credit: Future)
GameSir X4 Aileron review: design and features
Premium and clever design Clamping mechanism can be awkward Limited mobile app
The X4 Aileron adopts a fairly typical mobile controller design, although it protrudes less than some others, both lengthways and outwardly. There’s some subtle but vibrant RGB lighting around both analog sticks, which helps to liven up the total black finish.
The grips felt very comfortable in my hands, offering plenty of security thanks to the rubberized finish. One quirk of their design, though, is the sharp line running through their center.
This was initially jarring, but I quickly found this created an angle that allowed my fingers to get more purchase, which helps a great deal when using the two back buttons, as these are quite small; I would’ve struggled to use them comfortably otherwise. Overall, the X4 Aileron makes gaming on your phone feel similar to the best handheld games consoles .
It’s also built to a high standard, with premium materials used for the buttons and sticks. The latter of these feels especially smooth to the touch, while at the same time offering plenty of grip thanks to the texture of their outer edges.
The magnetic attachment for storing the X4 Aileron is well-engineered too, with both sides slotting together with a strong hold that’s also easy to remove when needed. This also helps to save space when traveling, as they fit snugly in the included hard-shell carrying case, which is similarly well-made.
(Image credit: Future)
The X4 Aileron just managed to fit over my phone with a case attached, although the ledges of the clamps didn’t quite hang over the sides as they’re seemingly designed to do. Regardless, the attachment was sufficiently secure to prevent any undue movement.
However, the same can’t be said when clamped to my phone directly, as the X4 Aileron is prone to sliding and tilting back and forth. In normal use, this wasn’t much of an issue, and rubber pads can be installed to prevent this scenario. It’s a shame, though, that these pads aren’t removable once stuck in place; a removable or adjustable method would’ve been welcome, especially at this price.
The clamp system in general isn’t the most elegant solution, and while its tightness is reassuring, lifting it by hand is a little awkward, as there’s no real place to grip it with your fingers. Consequently, I often found myself mispressing my phone’s screen when attaching and detaching the X4 Aileron.
This is a small usability issue in the grand scheme of things, but worth mentioning. I found the best way to attach and release the X4 Aileron was to slide my phone in and out of both portions – although I can’t say this is a method GameSir condones.
What’s more, the fact that turning on and off the X4 Aileron involves lifting the clamps is somewhat inconvenient if you need to reconnect for whatever reason.
Various customization options are available for the X4 Aileron via the GameSir app, including deadzone alterations for the triggers and sticks, as well as a quick trigger mode for binary rather than analog inputs. There’s no button remapping, though, which seems like a fairly big oversight, and no curve profiles for the sticks to more finely tune their responsiveness and sensitivity.
The only other adjustments are a few other minor functions and tweaks to the RGB, so it falls behind adjustments other peripherals allow for. Compared to many other controllers, including those made by GameSir, this is quite the paucity of options.
At least the app is stable enough, although oddly there were certain menus and sections that couldn’t be navigated with the X4 Aileron, and other areas where it could. Certain sections had no English text either, although thankfully this was a rarity and didn’t affect usability. A firmware update also failed to install despite several attempts, only succeeding after I re-paired the X4 Aileron to my phone.
(Image credit: Future)
GameSir X4 Aileron review: performance
Clicky buttons Poor stick placement Battery life not great
Despite its looks, the X4 Aileron doesn’t exactly feel like a traditional console controller. The buttons aren’t damped: instead, they actuate with an emphatic click, which provides plenty of feedback, but if you’re someone who prefers the silent, softer feel of standard gamepads, then these might not be to your liking.
The D-pad is especially clicky but very satisfying to use. Presses are easy in all directions and the rebound is very quick. The stock hat design is very amenable to rolling in multiple adjacent directions, which I appreciated when playing Mortal Kombat 11 .
Both the triggers and the sticks use Hall effect technology, which offers greater precision than their standard potentiometer counterparts. When playing Forza Horizon 5
The triggers don’t have as much travel as those on the best Xbox controllers or best PC controllers , so I didn’t quite get the same level of granular control over inputs, but I was still impressed. However, they do curve around to follow the contours of the X4 Aileron itself, which increases their surface area and makes for a more natural and comfortable finger placement.
One major gripe I have with the X4 Aileron, though, concerns the right joystick. Owing to the asymmetrical design, it’s positioned low down, which isn’t a problem on standard gamepads. But since there’s no middle portion to the X4 Aileron, it’s also much closer to the edge of each pad, rather than further inward.
This combination makes for awkward thumb placement, forcing me to either bend it uncomfortably to reach it, or grip the entire right pad much lower down than usual and therefore sacrifice a secure hold.
I found this especially problematic when playing Call of Duty: Modern Warfare 3 best PS5 controllers , then the issue may be even more egregious.
Connecting the X4 Aileron was straightforward enough, although waking it from sleep wasn’t always that seamless, as I had to re-clamp it to reconnect on occasion.
Battery life isn’t particularly impressive, as, after only a few hours of testing, each pad seemed to drop by about 15%. However, the readout provided in the GameSir app was inconsistent, sometimes oscillating in an instant and changing more drastically when reconnecting.
There were also occasions where only one of the pad’s battery readouts was displayed, requiring the other to be reattached for it to show. Perhaps these issues can be fixed in a firmware update.
(Image credit: Future)
Should I buy the GameSir X4 Aileron? Buy it if…
Don’t buy it if…
Also consider…
Swipe to scroll horizontally
Row 0 – Cell 0
GameSir X4 Aileron
Razer Kishi Ultra
Backbone One
Price
$99.99 / £99.99 / AU$169
$149.99 / £149.99 / AU$269.95
$99.99 / £99.99 / AU$179
Dimensions
3.85 x 3.05 x 1.77in / 97.8 x 77.5 x 45mm (w/out phone), 3.85 x 9.3 x 1.77in / 97.8 x 235 x 45mm (w/ phone)
9.63 x 4.36 x 2.53in / 244.6 x 110.7 x 64.3mm
10.14 x 6.94 x 3.7in / 257.6 x 176.3 x 94mm
Weight
6.5oz / 186g
9.4oz / 266 g
4.7oz / 138g
Connection type
Wireless (Bluetooth), wired (USB-C)
Wired (USB-C)
Wired (USB-C)
Compatibility
Android (phones)
iOS, Android (phones, tablets)
iOS, Android (phones, tablets)
Software
GameSir App (Android)
Razer Nexus App (iOS / Android)
Backbone App (iOS / Android)
How I tested the GameSir X4 Aileron
Tested on Google Pixel 7a Played various games on Xbox Cloud Gaming Plentiful gaming experience
I tested the X4 Aileron for several days, during which time I used it on my Google Pixel 7a, both with and without a case. I also used the GameSir mobile app for customizing and tweaking the controller.
I played a variety of games via the Xbox Cloud Gaming app, which GameSir claims the X4 Aileron is designed for. I played Forza Horizon 5 and Call of Duty : Modern Warfare 3 Mortal Kombat 11 to test button response.
I have been gaming on multiple platforms for decades, including mobile and handheld systems. I have also reviewed numerous controllers compatible with mobile devices.
Read more about how we test
First reviewed March 2025
