We've already seen some demos of the tech in action – albeit rather brief demos – and here's everything else we know about what's coming down the line. If you like the idea of a foldable phone, then you'd better get saving.
Best smartphones 2018
Best cheap smartphones 2018
1. SAMSUNG GALAXY X
Thanks to a demo at Samsung's developer conference, we now have a slightly better idea of what the Samsung Galaxy X is going to look like: small and chunky. Unfortunately we couldn't get a hands on with the device at that event or at the rumoured behind-closed-doors showing at CES 2019, though, suggesting there's still a bit of work to be done on it.
We know Samsung is going to call the screen the Infinity Flex Display, and it'll make its way into several devices in the future. However, we still don't know the name of the actual phone... it might be the Galaxy X or it might be the Galaxy F... or it might be something else altogether.
As best as we can tell, the front of the Galaxy X has two 4.6-inch screens, which become a 7.29-inch tablet when folded. The rear of the device has a third 3.5-inch screen that allows it to be viewed even when folded down. This indicates that the device will work via a series of intricate hinges.
Essentially, it's a gadget that can transition between a phone and a tablet, something developers will be able to take advantage of courtesy of Samsung's new One UI software.
In terms of when we can expect to see and hear more, the latest industry gossip says the phone will be shown off in a more finished form at MWC 2019 in February, though it still might not go on sale for several months after that.
As for UK prices for the Samsung Galaxy X and prices elsewhere around the world, we're hearing a price of at least $1,400 (£1,112 converted) is on the cards. Being an early adopter has never been cheap.
2. MOTOROLA RAZR
From the noises that Motorola has been making, it's not going to be far behind Samsung with a foldable phone, and apparently it's also going to carry the iconic Motorola Razr branding. It's going to be a flip phone then, but with a full foldable screen inside when you open it up.
These rumours have been around for a while. It was back in February 2017 that Yang Yuanqing, the CEO of Lenovo (which owns Motorola) told TechRadar: "With the new technology, particularly foldable screens, I think you will see more and more innovation on our smartphone design. So hopefully what you just described [the Motorola Razr brand] will be developed or realised very soon."
Since then we've seen Motorola file a patent for a two-screen folding phone that flips out to be used as a tablet. The patent describes two cameras, as well as hinges at the top, bottom and middle, and the ability to be propped up into a tent-like display mode. An unfolded screen size of 7 inches has been mooted for the Razr Motorola foldable phone.
As yet we haven't seen any leaked images of what the foldable Motorola phone might look like, but we do have a fantastic concept video from the talented folks at TechConfigurations. If the phone ends up looking as good as this, we'd be prepared to pay what's likely to be a very high price for it.
3. LG FOLDING SMARTPHONE
LG never likes to get left too far behind Samsung, and sure enough it's been one of the busiest companies in developing foldable screen tech – not just for phones but for televisions and other devices (see the image above). In recent months LG has confirmed it's working on foldable phones, without revealing too many other details.
In fact, we think folding LG displays could be used by other phone makers, including Huawei. We were therefore very unsurprised back in January to hear that LG had filed a patent showing off a "mobile phone with a flexible display which can be folded in half", including the diagrams shown below.
4. APPLE FOLDABLE IPHONE
Arguably the biggest name besides Samsung when it comes to foldable device rumours is is Apple – and from what we can tell the hardware might be excitingly close to being fully realised.
Back in November last year an Apple Inc-filed patent emerged for "Electronic Devices With Flexible Displays", which specifically details an electronic device comprising "a flexible display in the housing having a bending region that bends about a bend axis". The words "cellular telephone" were mentioned in the same document.
Since then it's been a little quiet on the foldable iPhone front, though we have seen the iPhone XS, iPhone XS Max and iPhone XR appear with very unfoldable screens. According to analysts, Apple is going to wait until 2020 to release a foldable phone – and it might well have 5G on board too.
Apple doesn't always rush in with new tech trends, so 2020 sounds about right, even if it's behind the rest. It's also likely to cost a lot of money, if we know Apple. As yet, there have been no further leaks, just a very well done concept video from TechConfigurations, and news that the device may come with a Samsung screen.
5. HUAWEI FOLDING PHONE
Last and absolutely by no means least is the folding phone that Huawei is working on. Last October, CEO of Huawei, Richard Yu, confirmed that the Chinese maker already had a working prototype of a flexible smartphone, and then in March of this year patent diagrams of a foldable Huawei phone emerged.
Since then, Huawei has reiterated its commitment to bringing out a foldable phone, primarily because smartphone users need more room on their screens to save them having to keep returning to their laptops for certain tasks. We've also seen another excellent concept video from TechConfigurations based on patent filings