OnePlus has officially announced the OnePlus X, bringing the company's smartphone portfolio to three.

The new OnePlus X follows quickly on from the OnePlus 2 "flagship killer", offering OnePlus fans a smaller and more manageable handset, but how does it compare to the mid-range Android competition?

Read on to find out how the OnePlus X stacks up against Google's Nexus 5X, HTC's One A9, Motorola's Moto X Play, Samsung's Galaxy A5 and Sony's Xperia M5. What are the differences and where does the OnePlus X sit in the mid-range field? You can also read our first impressions with the OnePlus X here, as well as see how it compares to the OnePlus 2 and OnePlus One here.

The OnePlus X measures 140 x 69 x 6.9mm and it comes in two models - a black glass and metal-framed version called Oynx and a limited edition Ceramic model. The Oynx model weighs 138g and the Ceramic model weighs 160g.

The closest device to the OnePlus X in terms of size is the Samsung Galaxy A5, which measures 139.3 x 69.7 x 6.7mm and is therefore almost identical. The A5 is the smallest and slimmest of the devices being compared here by a fraction, as well as the lightest at 123g, followed closely by the Google Nexus 5X at 136g.

The largest, thickest and heaviest device within this comparison is the Motorola Moto X Play measuring 148 x 75mm, featuring a curve between 8.5m and 10.9mm and hitting the scales at 169g. The Ceramic OnePlus X is the second heaviest, while the other devices sit at 143g and under.

The HTC One A9 and Samsung Galaxy A5 both offer metal builds, while the Sony Xperia M5, Nexus 5X and Moto X Play opt for plastic so if you want glass or ceramic, the OnePlus X is your only option. The Xperia M5 and the Moto X Play both have water repellant features, while the Nexus 5X and the HTC One A9 have fingerprint sensors. The Nexus also offers USB Type-C.

The HTC One A9 comes in four standard colour options, which is more than any of the other devices within this comparison, but the Moto X Play has the Moto Maker feature, which allows for the best customisation opportunities.

The OnePlus X offers a 5-inch display with a 1920 x 1080 resolution for a pixel density of 440ppi, which is the same as both the HTC One A9 and the Sony Xperia M5.

The Samsung Galaxy A5 also has a 5-inch display but the resolution drops to 1280 x 720 pixels, giving it a pixel density of 294ppi, which is the lowest of the bunch here.

The Nexus 5X increases the display size to 5.2-inches and offers 1920 x 1080, which in turn delivers a 424ppi, while the Moto X Play further ups the size to 5.5-inches but as it sticks to Full HD, the pixel density sits at 401ppi.

The OnePlus X, HTC One A9 and Xperia M5 therefore offer the sharpest and crispest displays out of these devices, but also the smallest.

As we always say, smartphone cameras are tricky to compare as it doesn't just come down to how many megapixels. Software plays a huge part in delivering a final decent shot so make sure you check out our reviews before you opt for one of these devices on camera megapixels alone.

For the sake of spec crunching though, the OnePlus X has a 13-megapixel rear snapper and an 8-megapixel front snapper. There are a range of features on board, as there are with the other devices here, but OnePlus is keen to push the 0.2-second autofocus as one of the main advantages.

The HTC One A9 and Samsung Galaxy A5 both come with 13-megapixel rear cameras, while the Google Nexus 5X sits closely behind with a 12.3-megapixel rear shooter. The Motorola Moto X ups the rear to 21-megapixels and the Sony Xperia M5 moves things along slightly further to 21.5-megapixels, with the Sony therefore taking the crown for the most rear megapixels.

The Xperia M5 also takes the win for the most front megapixels too, sporting a 13-megapixel snapper. All the others within this comparison offer 5-megapixels, except the One A9 that comes with a 4-megapixel UltraPixel front camera.

The OnePlus X comes with a Qualcomm Snapdragon 801 processor, 3GB of RAM and 16GB of internal memory, with a microSD slot for further storage expansion up to 128GB.

There are different processors within all the devices being compared here, but they are all octa-core chipsets, apart from the Samsung Galaxy A5 and OnePlus X that both come with quad-core chips.

The OnePlus X is up there with the most RAM however, with the HTC One A9 being the only other to offer a 3GB option. The Nexus 5X, Moto X Play, Galaxy A5 and Xperia M5 all have 2GB on board.

The Nexus 5X is the only device not to support microSD storage expansion and it comes in 16GB and 32GB models, while the Galaxy A5 and Xperia M5 offer the same storage capacities as the OnePlus X. The Moto X Play and One A9 come in a 32GB model as well as a 16GB model but as Android Marshmallow now allows you to combine internal storage and microSD storage, you might not need the extra internal memory.

The biggest battery capacity sits within the Moto X Play at 3630mAh, followed by the Nexus 5X at 2700mAh. The smallest is within the HTC One A9 at 2150mAh, followed by 2300mAh Galaxy A5. The OnePlus X sits right in the middle at 2525mAh.

This is where things get a little more interesting. The OnePlus X follows the same path as the recently launched OnePlus 2 and runs on the company's own OxygenOS. This user interface is built on Android 5.1.1 but it allows for more customisation and adds several enhancements, such as off-screen gestures and Dark Mode. You can read our separate story on some of the software features here

The Nexus 5X runs on pure Android 6.0 Marshmallow with no skin over the top so this device is Android in its rawest form, but the Motorola Moto X Play runs on Android Lollipop with hardly any extra apps and this will get an upgrade to Marshmallow soon.

The HTC One A9 runs on Android Marshmallow too but has a refined version of Sense 7 over the top. You still get the HTC skin, but a few things have been removed, such as the HTC browser, which makes for a cleaner experience.

The Samsung Galaxy A5 and Sony Xperia M5 both run on Lollipop with each company's respective skin over the top.

The OnePlus X Oynx is the cheapest of the devices being compared here, costing £199. The Ceramic model is a little more expensive at £269 but still cheaper than any of the other devices.

The HTC One A9 has been priced in the UK at £429, which is the most expensive of the devices compared here. The Nexus 5X follows closely behind at £379.99, while the Motorola Moto X Play starts at £279 and the Samsung Galaxy A5 at £299. We can only find a US price for the Sony Xperia M5, which currently sits at $439.

All of the six devices within this comparison have strengths and weaknesses and they are all good mid-range devices in their own right. They aren't flagships but they do have some flagship qualities.

The OnePlus X is the cheapest of the devices available, even if you opt for the limited edition Ceramic model, although you will need an invite to get your hands on either.

Its cheap price tag brings one of the smallest and lightest, as well as one of the sharpest displays and larger RAM capacities. The OnePlus X doesn't have the largest battery capacity but it does sit in the middle and it has some good camera specs too, so certainly a worthy competitor based on the numbers.