A tool so specific can almost feel like it's more of a gimmick than an actual piece of equipment that is useful. Although that can be the case with some tools, it's definitely not with hedge trimmers. These powered tools are made for one and only one use and that is, as you'd expect, to keep the hedge in your garden in top shape.
Easy to use, hedge trimmers are the best tools to help you shape your hedges and prevent them from overgrowing which can make your garden look like you've abandoned the place. Although their operation is simple, hedge trimmers are not easy to make a choice on which one to get. There are plenty of features you have to go through before making your final decision.
What to Look for in Hedge Trimmers

Power
The first and most important thing you need to look out for is the power delivery of hedge trimmers. The amount of power they can operate at depends on their power source but just because something is more powerful you shouldn't always go for it. Although a more powerful hedge trimmer is going to be better, if it's anything out of reach for what you'll do regularly there's no need to opt-in for that extra power.
Length
Hedge trimmers come in varying blade lengths which determine how you'll use your trimmer. Trimmers with longer blades are going to be unwieldy but they can make for a more even trimming process. For the majority of hedges, a trimmer with a 45 cm blade will do just fine. But if you have larger hedges then a trimmer with a 50 cm blade should be on your mind.
Blades
Talking about the blade of a trimmer, it can be quite different from the one your neighbour has. The blades can be either single or double-sided and the distance between the teeth can be different too. A single-sided blade is easier to use and also safer while a double-sided one is a lot faster. The teeth gap will be about 2.5 cm on a standard trimmer but you can buy hedge trimmers with smaller gaps if you want an even faster trimming experience.
Weight
The weight of the trimmer will determine how portable it's going to be. Of course, heavier trimmers may be burdensome to carry but they are almost always more capable. It's best that you strike a balance between weight and portability to get the best of both worlds.
Maintenance
No matter the hedge trimmer you go for you should always focus on the level of maintenance it requires on a regular basis. If you have to tend to it as you do to your car you might want to avoid it. You should definitely keep the blades sharp and the tool clean but anything more than that implies that it's a more complex tool.
Noise
The amount of noise a trimmer produces can be either annoying or reasonable. There really is no way around it other than to wear earplugs if you need the power of a noisier trimmer. Typically that is the case with more powerful trimmers.
Durability
A trimmer that will serve you for years to come is something everyone wants but that isn't always the case. At least not with less reputable brands. A good rule of thumb is that the brand of trimmers you see being used the most is the one to go for as that's not the case for no reason.
Safety
Since you're working with a spinning blade, it's important to consider the safety of a trimmer. Safety features such as tooth extensions and automatic power cuts are the first features you should consider when it comes to the safety of a trimmer.
Features
Talking about features, you should keep in mind that there are plenty of them but you should go for the ones that make sense for you. Some of them include a wraparound handle that makes it easier to hold the trimmer as well as dual switches which require you to use both hands when using the trimmer.
Types of Hedge Trimmers

Petrol
The more powerful hedge trimmers in this case are petrol-powered ones. But bear in mind that petrol hedge trimmers are also going to produce a lot more noise and they also require more maintenance. But overall petrol hedge trimmers are a great option when you want a bang-for-buck solution that won't fail you when it comes to doing a lot of work efficiently.
Electric
As you'd expect a battery operated hedge trimmer is more convenient when compared to petrol ones. This is because there is a lot less noise being produced when using them and very little maintenance is needed especially with newer models. A battery operated hedge trimmer is well adequate for sorting out a small garden but it won't perform as well on more time-consuming hedges. They may have the power but the delivery of that power level won't last as long as with a petrol trimmer.