The HTC One M8 has been a popular device but with 2014 behind us, anticipation is rising about what will come next for HTC's flagship.

It should come as no surprise if it's known as the HTC One M9, following the model numbering of previous years. The name HTC Hima has also surfaced, which could be the next-gen HTC flagship's codename. It is also likely that HTC will drop the brackets around the name of the phone as the name "HTC One M9" appeared on an official HTC website in that form.

The rumours are starting to flow, so to help you navigate through the mire of speculation, we'll be keeping track of what's being said and draw out some of the more logical conclusions, including what we want to see.

HTC One M9 release date

HTC has sent out invitations for the HTC One M9 launch event, which will be held on 1 March 2015.

The launch event will be in Barcelona on the eve of Mobile World Congress 2015. Invitations were sent out to the press on 16 January confirming the M9 release date and the phone recently appeared on the official HTC website's coding so it is certainly on its way.

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HTC

HTC has eschewed large events in the past few years, choosing instead to hold its own. This was the case for the HTC One M7 and M8, both of which were launched separately from Mobile World Congress.

The M8 launch was notable because the device was available in stores the same day, but that lead to a large number of leaks prior to launch. We suspect the HTC One M9 availability will be a few weeks after MWC, around 20 March.

HTC One M9 design and build

We'd predict the M9 will follow the lines of the M8, with a similar aluminium body, sculpted to fit into your hand. You can expect BoomSound speakers to the front, although recent launches - the HTC Desire Eye and HTC Desire 826 - have moved to a front slit speaker, rather than the microdrilled grille of the past. This might allow the M9 so be slightly smaller.

Leaked images claiming to be the HTC One M9 suggest that from the front the design will be very much the same. This design is now appearing frequently online, suggesting this model is certainly doing the rounds.

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Nowhereelse

Early rumours said 7mm thick, but that's almost immaterial, because it's the device in its entirety that's important. Dimensions from leaker @upleaks said 144.3 x 69.4 x 9.56mm, which are very, precise to be pulled out of thin air. That's slightly larger than the M8, but there's no way of verifying it.

The HTC One M8 had an IPX3 rating that was never really talked about. With the Desire Eye making a move to IPX7, we get the feeling that HTC will be looking to include some waterproofing to stay competitive against the likes of Samsung and Sony.

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Two new photos - posted by Phandroid, which cited a reliable unnamed source close to HTC - have provided clear shots of the front of the device. We can see from the photos that HTC moved the power button from the top of the device to the right side, similar to Apple's iPhone 6, and it moved the volume rocker and power buttons lower on the right side. The same site also published pictures of the rear, revealing a normal camera rather than the Duo camera on the M8.

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Phandroid

Recent rumours are pointing to an aluminium silicon-carbide composite body, which might help with heat dissipation. According to @upleaks, we can expect a variation of colours including grey, silver and gold.

There have been some variations in the models getting the leak treatment: Although the more common is that shown above - with a square camera hole, there is another model appearing with a slightly different design, shown below.

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weibo

This might be that HTC is using decoy models to avoid spoiling the surprise, or it might be that several different models will be announced on launch day. There's talk of the HTC One M9 Plus, a larger version with a fingerprint scanner, which is thought to be a different model to the M9 we're anticipating.

It looks like the HTC One M9 will be getting the gold treatment too. This photo leaked onto nowhereelse.fr showing off the colour variant.

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Nowhereelse

But the clearest indication of what the HTC One M9 looks like actually comes from a German retailer, Cyberport.de. It posted a shop page for the new phone with some official looking renders that show the phone in all its glory. And in silver and gold and dark grey colour schemes, which you would expect from HTC.

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Cyberport.de

The images comply with three purportedly official leaked videos too. First posted on YouTube by Twitter leakmeister @upleaks, the clips are supposedly for HTC marketing use and have since been removed. But not before we managed to take a whole stack of screengrabs though.

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Upleaks - YouTube

HTC One M9 display

Early rumours suggested that the M9 will have a 5.2-inch Quad HD display, i.e., 2560 x 1440 pixel resolution, giving you 564ppi. That display is the same resolution as the LG G3 and the Samsung Galaxy Note 4, on a slightly smaller scale.

That resolution might just be speculation though - a case of keeping up with the Joneses - and we'd certainly like to see that screen size in the next HTC premium device. Having used the HTC Desire Eye, which has a 5.2-inch full HD display, we think there's a lot going for it.

A photo of a front panel recently appeared at nowhereelse.fr, a website that's accurately uncovered details about various smartphone components in the past. This is for a 5.2-inch display, potentially for the M9, but the site says it can't accurately verify the information.

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Nowhereelse

Other rumours suggest HTC will stick to 5-inch full HD, as with the M8, and a leaked set of alleged AnTuTu benchmark scores seem to confirm those suspicions. As we approach the launch of the next-gen HTC One, rumours seem to have settled on 5 inches for the M9.

We'll happily take it either way. We'd take better battery over under-utilised display resolution, but we know the spec sheet is important to HTC. Expect 5 or 5.2 inches.

Under the skin

The inital run of rumours suggested that the HTC One (M9) will have a Qualcomm Snapdragon 805 chipset, with 3GB of RAM. The 805 is a step-up over the 801 that the M8 houses, and is currently found in the Nexus 6 and the Galaxy Note 4, both very powerful devices.

Of course that's not all that Qualcomm has in stock: there's the octa-core 64-bit Snapdragon 810 too, with Adreno 430 graphics claimed to be 30 per cent more powerful than the Adreno 420 of the 805. Qualcomm has slated the 810 for early 2015 devices, fitting with HTC's launch plans.

This chipset was mentioned by @upleaks, stating that the HTC M9 would have the SD 810 with 3GB RAM. And the leaked AnTuTu benchmark seems to back that up.

The Snapdragon 810 appeared again in a leaked benchmark test on Geekbench 3.0 which showed 1.55GHz and 3GB of RAM pushing out a multi-core score of 3587 making it lower than the alleged score of the rumoured Samsung Galaxy S6.

The 64-bit is worth a mention, as Android 5.0 Lollipop supports 64-bit architecture, so that's likely to be a big push for device manufacturers in the future, hopefully bringing added performance with lower energy demands.

Without any concrete information, however, this is mostly just speculation based on Qualcomm's road map and HTC's longstanding use of the chip manufacturer's hardware.

The battery is said to be 3,500mAh by some, 2840mAh by others. Although bigger is often better, the M8 performed well on the 2600mAh battery and with advancing chipset technology, it might have the endurance it needs.

HTC Sense 7 and Android 5.0 Lollipop

Lollipop will be arriving on Sense 6 devices before the M9 is due to launch, but you can be certain that the M9 will launch with Android 5.0 and a refreshed version of Sense. Indeed, the leaked benchmarks suggest it will even come with Android 5.1.

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AnTuTu

HTC has been actively offloading apps from the core OS (e.g.: Blinkfeed, Camera, Zoe) into Google Play for more frequent updates, so Sense 7 is likely to bring in a run of changes separate from some of HTC's headline apps.

Videos claimed to be officially HTC made surfaced for a short while, showing some of the new features of Sense 7 - such as Blinkfeed having "meal time suggestions", but they have since been removed. You can still check out some of the screengrabs taken, however, including the ability to add themes to the homepage.

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Upleaks - YouTube

On the subject of backgrounds and themes, Twitter user @LlabTooFer has been posting what he claims to be wallpapers taken directly from a dev phone he's been using. Making one available to download every day through his Mega account, he has released several already and says that he will continue until the launch on 1 March.

What we can glean from the images is that because they are 2160 x 1920 and will be scrollable, the most likely screen resolution of the HTC One M9 will be Full HD 1920 x 1080.

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@LlabTooFer

BoomSound with Dolby

BoomSound is one of the highlights of the HTC One family and it's something that HTC is right to stick to. According to Nowehereelse sources the speakers will be on the front as was the case with the HTC One M8.

The HTC Desire 826 launched with Dolby support for the BoomSound speakers and headphones. That looks like a logical pairing with HTC saying that the headphones that ship with the 826 being "audiophile grade". That may well be the focus for the HTC One M9 too.

HTC One M9 cameras

The camera has been the biggest point of contention on the HTC One M8. It's also likely to be a core focus on the M9, but at the moment there's no telling which direction HTC will move in.

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Nowhereelse

There's a strong argument for ditching the Duo Camera arrangement of the M8, as well as a question mark over the value of UltraPixel as a brand name.

It might be that we have an UltraPixel sensor at 8-megapixels, it might be that HTC changes tack and adopts the 13-megapixel sensor it's using in other devices, like the HTC Desire Eye. Optical image stabilisation would be widely welcomed and some rumours are pairing OIS with a 16-megapixel sensor.

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nowhereelse

A rumour from @upleaks suggested a 20.7MP sensor and having seen the Desire 826 with UltraPixel on the front for selfies, we strongly believe that the HTC One M9 will have the same arrangement. The same arrangement if suggested by Nowhereelse, whose leaked photo also show a square hole for the camera on the rear, with dual LED flash.

Phandroid also published pictures of a similar looking rear along with some images claimed to have been taken by a HTC employee with the HTC One M9 (under the manufacturer names of HTC 0PJA10 or a HTC 0PJA13). These were cropped to a 16:9 ratio, but if full sized would indeed corroborate the 20-megapixel sensor theory.

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Phandroid

We will update this feature when credible rumours and leaks appear. Stay tuned.