Electric bikes are a great choice for city riding, taking the sweat out of commuting errands, and e-bikes that fold are even better. No more worrying about finding space for your bike at home, on public transport, or at the office just fold it down and tuck it neatly out of the way.We've put a wide range of folding e-bikes to the test, so we can bring you a definitive listing of the very best around. We've put all these bikes through their paces in real world conditions mastering their folding mechanisms, testing their battery life, assessing their comfort, and gauging their overall suitability for taking on the streets.Folding e-bikes are typically heavier than their non-folding counterparts due to the need for robust frames with tough joints, but even that's becoming less of an issue. The MiRider One, which is our number one pick for the best folding e-bike of 2021, weighs just 17.2kg, making it easy to lift and carry.Don't be put off by the price, either folding e-bikes are also cheaper than you might expect. They're still a considerable investment, but prices are only a little higher than similarly specced non-folding models. We've tested bikes from across the entire price bracket, and some of the least expensive came up on top.Once you've chosen a folding electric bike, make sure you also pick up a great bike lock to keep it secure, and a set of bike lights if it doesn't have them built in.Surprisingly affordable and a joy to ride, the MiRider One is the best folding e-bike of 2021 (Image credit: MiRider)The MiRider One is a very impressive folding e-bike it packs down in under a minute, it's one of the lightest models around, and it's remarkably affordable. It's extremely comfortable to ride as well, and when we tested it, we were surprised at just how solid its magnesium alloy frame felt. There are no compromises; it doesn't feel like a folding bike at all.The MiRider One's power controls are simple to use, and all within easy reach of your thumb. When it's time to pack the bike away, the frame folds neatly in half, the seat post retracts, and the handlebar stem folds down. The pedals also fold in, and the whole neat package can be tucked inside a weatherproof case.It doesn't have the range for a long touring holiday, but if you're looking for a folding e-bike for everyday riding, the MiRider One is the best around.The GiCycle GX is ideal for commuters thanks to its sleek, fuss-free design (Image credit: GoCycle)The latest edition of the GoCycle GX is also a superb folding e-bike, and comes highly recommended if you're looking for something a little more stylish. Like the MiRider One, the GoCycle GX uses magnesium alloy to keep the frame weight down, and gives a comfortable ride that you wouldn't expect from a bike that folds down so small. Unlike the MiRider One, which is designed to be as simple to use as possible, the GoCycle GX lets you personalize your ride with a smartphone app that you can use to tweak the bike's settings. It also serves as a handy trip computer if you attach your phone to the handlebars, providing a speedometer, odometer and various fitness tracking statistics.The GoCycle GX has a particularly sleek design that's been thoughtfully planned with commuters in mind. A chain guard protects your cuffs from oil, and internal routing helps protect the cables from damage when the bike is being moved in its compacted state.This engineering doesn't come cheap though, and the only real drawback of the GoCycle GX is its price. It's not extortionate for the build quality and battery power you're getting here, but it's towards the higher end.The M6L Electric is seriously fun to ride thanks to its zippy front hub motor (Image credit: Brompton)The Brompton M6L Electric is a beautifully engineered folding e-bike, which is no surprise considering its heritage. British company Brompton has been building folding bikes since the 1970s, and has now added a 250W motor and 300Wh battery to its its signature curved frame. It's a combination that works brilliantly, if your wallet can handle the price tag.The M6L Electric feels surprisingly lively on the road, which can be attributed to a front hub motor developed in collaboration with Williams Advanced Engineering a company better known for its work in Formula One and Formula E. It feels very different to a bike with a rear hub motor (like the others on this list), and we found it a lot of fun; it feels like you're being pulled along.Whereas many folding e-bikes have a battery integrated into the frame, the M6L Electric's power pack is mounted on the front. It's not particularly sleek, but means that you can easily detach the battery for charging rather than having to plug in the entire bike, and the bike is much lighter and easier to carry upstairs with the pack removed.The Mate City is a great-looking e-bike, but remains quite bulky even when folded (Image credit: Mate Bike)The Mate City is a real conversation, as our reviewer discovered, with its stylish frame (available in a range of subtle and not-so subtle paint colors) attracting a lot of admirers. It's solidly built too, with a robust frame that packs down fast, and is easily adjusted to suit your height and preferred riding position.A small LCD display on the handlebars displays the battery status, your speed, and the time and distance of your current trip. It's a handy addition that avoids the need to mount your phone on the bike, which is always a little risky if you're prone to forgetfulness and accidentally leave your handset behind.The downside is that the Mate City is seriously weighty, tipping the scale at 22.5kg with the battery attached. You won't be breezing up and down stairs with it, but if your main reason for choosing a folding e-bike is ease of storage at either end of your journey, it's definitely worth your consideration.(Image credit: E-Trends)If you're on a budget, the E-Trends Fly is an excellent option. It was launched at £899 (about $1,200 / AU$1,600) but has dropped as low as £699 (about $3,400 / AU$1,300) since then, making it excellent value for any electric bike let alone a folding one, which is a trickier feat of engineering.The ride is comfortable, and its controls are easily accessible with a touch of your thumb. There's also a pushing mode, which gives you a little help from the battery when you need to hop off and wheel it along the sidewalk for a stretch.The design is somewhat odd, and our reviewer commented that it looked less smart and cohesive than other electric bikes, but for such a modest price that's a relatively minor complaint. It's worth noting that it uses V-brakes, which proved effective in our tests, but don't provide the same stopping power as the disc brakes used by the other folding e-bikes in this roundup.