Robot mower listings are full of jargon: RTK, LiDAR, IPX6, network RTK, AWD. Below, each one explained, with the answer to what you probably want to know: do I need it?
Boundary wire
Also called: perimeter wire, wired mower
A thin, low-voltage wire pegged or buried round the edge of the lawn and round flower beds. The mower picks up a signal from the wire and turns back when it reaches it. It is the oldest and simplest way to keep a robot mower on the lawn. More detail.
Do I need it? Yes, if you want the lowest price, your lawn has no Wi-Fi or phone signal, and you don't mind a day of pegging the wire in.
Skip it if you change your garden layout often, you dig borders a lot (a cut wire stops the mower), or you want to redraw boundaries from your phone.
25 of the 80 mowers we compare are boundary-wire models.
Guide wire
An extra wire on boundary-wire mowers, run from the charging station across the lawn. The mower follows it home and can use it to reach far corners or a second lawn.
Do I need it? Yes, if you have a boundary-wire mower and a long, narrow or split lawn.
Skip it if you are buying a wire-free mower: it finds its own way home.
Wire-free
Also called: boundary-free, perimeter-wire-free, virtual boundary
The mower stays on the lawn without any wire. You draw the edges on a map in the app, usually by driving the mower round the lawn once with your phone like a remote-control car. It then uses satellites, a laser scanner or cameras (or a mix) to know where it is. More detail.
Do I need it? Yes, if you don't want to lay a wire, or you want to change boundaries and no-go zones from your phone.
Skip it if you care most about price and your lawn is a simple shape: a boundary-wire mower does the same job for less.
50 of the 80 mowers we compare are wire-free.
GPS or GNSS
Also called: satellite positioning
Positioning from satellites, as in your phone. GNSS is the umbrella term that covers GPS (USA), Galileo (Europe), GLONASS (Russia) and BeiDou (China). On its own it is usually only accurate to a few metres, which is not good enough to mow up to a flower bed, so mowers add RTK corrections on top.
Do I need it? Always part of an RTK mower. It is not a feature to look for on its own.
Can I skip it? Yes. And don't be swayed by a listing that says only "GPS" with no RTK: on a mower that is usually for theft tracking, not for navigating.
RTK
Also called: Real-Time Kinematic positioning
A way of correcting satellite positions from a few metres down to a few centimetres in good conditions. A reference receiver at a known, fixed spot works out the satellite errors and sends corrections to the mower. It comes in two forms: your own reference station in the garden, or corrections sent over the internet (network RTK). More detail.
Do I need it? Yes, if your lawn is mostly open sky: RTK gives straight, neat stripes and accurate edges without a wire.
Skip it if your lawn is surrounded by tall trees or sits close to a house or high walls. Satellites get blocked there and an RTK-only mower can lose its position. Choose LiDAR or a mower that combines RTK with cameras.
RTK reference station
Also called: base station, RTK antenna, beacon, EPOS RS1 (Husqvarna)
A small antenna you mount in your garden, often on a pole or the side of the house, with power and a clear view of the sky. It sends corrections to the mower by radio, so the mower does not need Wi-Fi or 4G to navigate.
Do I need it? Yes, if your lawn has no Wi-Fi and no reliable phone signal, but it does have open sky and somewhere to mount the antenna.
Skip it if you don't want anything installed (pick network RTK or LiDAR), or there is no spot with open sky and power.
12 of the 80 mowers we compare have this.
Network RTK
Also called: NRTK, cloud RTK, iNavi (Mammotion), EPOS via Husqvarna Cloud
RTK corrections sent over the internet from a network of reference stations run by the maker or a partner, so there is no antenna to install in your garden. The mower needs a connection on the lawn while it mows: either its own 4G or your Wi-Fi. More detail.
Do I need it? Yes, if you want RTK accuracy with nothing to install, and your lawn has good 4G or Wi-Fi.
Skip it if your lawn has weak phone signal and no Wi-Fi. Also check whether the 4G is free for good or becomes a paid plan.
21 of the 80 mowers we compare have this.
LiDAR
Also called: laser radar, 3D LiDAR
A spinning laser on top of the mower that measures the distance to everything around it many times a second, and builds a 3D map of your garden. The mower then finds its place by recognising trees, walls and fences. It needs no satellites and no internet. More detail.
Do I need it? Yes, if you have trees, a house or tall hedges round the lawn, no Wi-Fi at the grass, or you simply want the mower that copes with the most gardens.
Skip it if your lawn is a large open field with few landmarks and you want the lowest price: RTK may be cheaper and works well there.
12 of the 80 mowers we compare have this.
Vision navigation
Also called: AI camera, AI vision, camera navigation, VSLAM
Cameras on the front of the mower recognise grass, edges, paths and objects, and some use them to map the garden (VSLAM means mapping with cameras). Many mowers use cameras alongside RTK or LiDAR for spotting obstacles; a few use cameras alone.
Do I need it? Yes, as a second system: cameras alongside RTK or LiDAR are worth having for spotting toys, hoses and animals.
Can I skip it? Avoid camera-only navigation if your lawn edges are unclear or the grass runs into gravel or beds without a clear line. Cameras also need good light.
47 of the 80 mowers we compare have this.
Sensor fusion
Also called: multi-sensor navigation, hybrid navigation
The mower combines two or three of the systems above, such as RTK plus cameras, or LiDAR plus RTK plus cameras. When one drops out (satellites blocked by a tree, say) the others keep it on track.
Do I need it? Yes, if your garden has both open lawn and shady or built-up corners.
Skip it if your lawn is simple and open, and you want to keep the price down.
Drop-and-mow
Also called: no-setup mower, boundary-free camera mower
A small mower you put on the lawn and switch on. It uses sensors underneath or a camera to tell grass from not-grass and turns back at the edge. No wire, no map, usually no app. More detail.
Do I need it? Yes, if you have a small, simple lawn surrounded by paving or gravel, and you want zero setup.
Skip it if your lawn runs into flower beds with no hard edge, you have a pond or a drop, or you want app control and schedules.
5 of the 80 mowers we compare are drop-and-mow models.
Wi-Fi at the lawn
Whether your home Wi-Fi reaches the grass, not just the house. Some wire-free mowers need Wi-Fi across the whole lawn to navigate; others use it only for app updates. More detail.
Do I need it? Check it before you buy a network-RTK or Wi-Fi-navigated mower: stand at the far end of the lawn and see whether your phone stays on Wi-Fi.
Skip it if you are buying a LiDAR, own-station RTK or boundary-wire mower: none needs Wi-Fi to mow.
Built-in 4G
Also called: cellular, mobile data, eSIM, SIM card
A mobile data connection inside the mower, like a phone's. It lets the app reach the mower from anywhere, powers GPS theft tracking and, on network RTK mowers, carries the corrections it needs to navigate. It usually comes with a free period, after which some brands charge. More detail.
Do I need it? Yes, if your lawn has no Wi-Fi, or you want to control the mower and track it if stolen while you are away from home.
Skip it if your Wi-Fi covers the lawn and you are happy to control the mower only when at home.
32 of the 80 mowers we compare have this.
Subscription or connectivity plan
Also called: Connect+ (Navimow), 4G renewal, data plan
A yearly fee, usually after a free first year or three, to keep the 4G connection and app features such as remote control and theft tracking. What you really want to know is whether the mower still mows if you stop paying. More detail.
Do I need it? Only if the mower cannot navigate without it and your lawn has no Wi-Fi. Our 5-year cost includes the plan in that case.
Skip it if the mower keeps mowing without it (check this on its model page), and you can live without remote control from outside the house.
Bluetooth
Short-range connection between your phone and the mower, typically up to about 10 metres. Used for setup and driving the mower round the lawn to map it.
Do I need it? It comes as standard on app-controlled mowers; it is not something to choose on.
Can I skip it? You can't, but don't rely on it day to day: you have to be standing near the mower.
App control
The phone app where you draw the map, set mowing times and cutting height, and see where the mower is. Almost every wire-free mower needs the app for setup.
Do I need it? Yes, if you want to set schedules, no-go zones and different heights for different areas.
Skip it if you want a mower with no smartphone involved: look at boundary-wire models with a keypad, or drop-and-mow models.
OTA updates
Also called: over-the-air updates, firmware updates
The maker sends software improvements to the mower over Wi-Fi or 4G, like phone updates. They can add features or fix navigation problems after you buy.
Do I need it? Yes, if you are buying a newly launched model: early updates often fix teething problems.
Can I skip it? Yes. It is not a reason to buy one mower over another, but a brand with no updates for a year is a warning sign.
Rated area
Also called: working area, max lawn size, m²
The largest lawn the maker says the mower can keep cut, in square metres, usually mowing most days of the week in good conditions. Complicated gardens, long grass in spring and wet weeks all reduce what it really manages.
Do I need it? Always check it. Pick a mower rated comfortably above your lawn size, especially if the lawn is split into sections or has lots of beds and trees.
Can I skip it? Don't pay for a much bigger rating than you need: you pay for battery and speed you won't use.
Slope rating (%)
Also called: max incline, gradient
The steepest slope the mower can climb, given as a percentage: how many centimetres it rises for every 100 cm across. 100% is 45 degrees; 45% is about 24 degrees; 30% is about 17 degrees. To measure yours, rest one end of a 1 m spirit level on the slope, hold it level, and measure the drop from the other end down to the grass in cm. That number is roughly your percentage. More detail.
Do I need it? Yes, if your lawn has any bank. Buy a mower rated above your steepest part, as wet grass makes slopes harder.
Skip it if your lawn is flat: then slope rating hardly matters.
Edge slope limit
Also called: boundary slope, max slope at the edge
Many makers allow a lower slope at the lawn edge than in the middle, because a mower that slips at the edge can leave the lawn. Look for it in the small print of the spec sheet or manual.
Do I need it? Yes, if your lawn edge runs along a bank, a drop, a pond or a road.
Skip it if your edges are flat even if the middle of the lawn slopes.
AWD, 4WD, RWD, 2WD
Also called: all-wheel drive, four-wheel drive, rear-wheel drive
How many wheels are driven. Most robot mowers drive the two back wheels (RWD or 2WD). All-wheel drive (AWD or 4WD) drives every wheel, which grips far better on steep or wet ground. More detail.
Do I need it? Yes, if your lawn has slopes over about 45%, soft ground, or stays damp for long spells.
Skip it if your lawn is flat or gently sloping and drains well: two-wheel drive is cheaper and lighter.
7 of the 80 mowers we compare have this.
Multi-zone mapping
Also called: zones, multi-map, multiple lawns
The mower can keep more than one lawn area on its map, such as a front and back lawn, and mow them on different days or at different heights.
Do I need it? Yes, if you have separate lawns or a lawn split by paths, a patio or a drive.
Skip it if you have one simple lawn.
Channels or passages
Also called: paths, transfer paths, corridors
Routes you draw in the app that the mower uses to travel between zones without mowing, such as across a patio or along a side path.
Do I need it? Yes, if the mower has to cross a path or hard surface to reach another lawn.
Skip it if your lawn is one connected area.
Minimum passage width
Also called: narrowest gap
The narrowest gap the mower can reliably drive through, such as a gate or the space between a shed and a fence.
Do I need it? Yes, if your lawns are joined by a narrow gap. Measure it and compare.
Skip it if your lawn is one open area.
No-go zones
Also called: exclusion zones, forbidden areas
Areas you mark on the map for the mower to avoid, such as a pond, a vegetable patch, a wildflower corner or the dog's favourite spot. On boundary-wire mowers you make them by running the wire round them.
Do I need it? Yes, if you have anything on the lawn the mower should stay away from.
Can I skip it? Not really an option: every wire-free mower has them. Check how easy they are to change in the app.
Mapping
Also called: auto-mapping, boundary walk, virtual boundary setup
How you teach the mower your garden. On most wire-free mowers you drive it round the edge once with your phone. Some LiDAR and camera mowers can map the lawn on their own.
Do I need it? Yes, if you want the quickest setup: look for auto-mapping, and check reviews for how well it finds the edges.
Skip it if you don't mind spending 30 to 60 minutes walking the mower round once.
Systematic or random mowing
Also called: straight lines, stripes, random pattern
Wire-free mowers usually mow in straight, neat lines, like a person would. Boundary-wire mowers usually wander in a random pattern and bounce off the wire. Both leave an even cut over time; random mowing just takes more hours to cover the lawn.
Do I need it? Yes, if you want a striped look and the lawn finished quickly: choose systematic.
Skip it if you only care that the grass stays short: random mowing does that fine.
Cutting width
Also called: deck width, mm
How wide a strip the mower cuts in one pass, in millimetres. Wider means fewer passes, so it finishes a big lawn faster.
Do I need it? Yes, if your lawn is large and you want it done in fewer hours.
Skip it if your lawn is small: a narrower deck also gets into tighter spots.
Cutting height
Also called: height of cut, mm
The range of grass heights the mower can leave, in millimetres. Electric adjustment means you change it in the app; manual means turning a knob on the mower.
Do I need it? Yes, if you like grass longer in a dry summer or shorter for a neat look: check the range covers both. Electric adjustment helps if you change it often.
Skip it if you will set it once and leave it.
Pivoting blades and blade disc
Also called: razor blades, mulching
Most robot mowers cut with small razor-like blades on a spinning disc. The blades swing back if they hit something hard. They trim a little every day and leave the tiny clippings on the lawn as natural feed (mulching), so there is no grass box to empty. Blades need replacing every few weeks to months.
Do I need it? Blades wear out, so factor in their cost: our 5-year cost includes them.
Can I skip it? Yes: blade designs rarely decide anything between brands.
Edge cutting
Also called: edge trimming, cut-to-edge, Cut-to-Zero (Worx), TruEdge (ECOVACS)
Most robot mowers leave a strip of uncut grass along walls, fences and beds, because the blades sit inside the body. Edge cutting uses an offset deck, an extra disc or a string trimmer to cut closer. Even then most leave a few centimetres next to walls. More detail.
Do I need it? Yes, if you have long straight edges against walls or fences and hate strimming.
Skip it if your lawn edges run into borders or are level with paving the mower can drive onto: it mows those edges fine anyway.
16 of the 80 mowers we compare have this.
Obstacle detection
Also called: collision sensors, bump sensors, ultrasonic, ToF, radar
How the mower notices things in its way. Bump sensors stop it after it touches something; ultrasonic, radar and ToF (time-of-flight) sensors measure distance before contact; cameras and LiDAR can see and steer round objects.
Do I need it? Yes, if you have children's toys, garden furniture, pets or windfall fruit on the lawn: look for camera or LiDAR obstacle avoidance.
Skip it if your lawn is kept clear: bump sensors are fine.
Animal or wildlife detection
Also called: hedgehog detection, pet detection, night mode
Features that aim to spot animals and stop, or that prevent mowing at night. In research tests of 19 models, all but one had to touch a hedgehog before reacting (apart from a single incident), so no mower is proven hedgehog-safe. More detail.
Do I need it? Yes, if you want an extra safety net, but treat it as a back-up. What makes far more difference is mowing only in daylight.
Can I skip it? Yes, as long as you mow only in daylight. Never rely on it instead of a daytime schedule.
5 of the 80 mowers we compare have this.
Lift and tilt sensors
Also called: blade stop
The blades stop straight away if the mower is lifted or tipped. It is a standard safety feature.
Do I need it? Yes, and nearly every mower has it. Check it is listed if you have children or pets.
Can I skip it? No. It is standard, so it is not a reason to choose one mower over another.
Rain sensor
Also called: rain delay, weather-aware scheduling
The mower detects rain and goes back to its charging station, or the app checks the weather forecast and skips mowing. Mowing soaked grass leaves ruts and clumps. More detail.
Do I need it? Yes, if you have clay soil or a lawn that churns up when wet.
Skip it if your lawn drains well; most mowers can be paused from the app on wet days.
28 of the 80 mowers we compare have this.
IP rating (IPX5, IPX6)
Also called: water resistance
How well the mower keeps water out. IPX5 means it can take a low-pressure water jet; IPX6 means it can take a powerful jet. It tells you rain is fine, but check the manual before using a hose, and never use a pressure washer.
Do I need it? Every mower lives outdoors: IPX4 or better is normal.
Can I skip it? Yes: don't pay extra for a higher IP rating alone. It rarely separates mowers.
Anti-theft: PIN, alarm, GPS tracking, geofence
A PIN stops anyone else using the mower. An alarm sounds if it is lifted. GPS tracking shows where it is on a map, usually over 4G. A geofence warns you if it leaves your garden. More detail.
Do I need it? Yes, if your lawn is visible from the road or easy to walk onto: GPS tracking makes recovery possible, and a PIN makes it useless to a thief.
Skip it if your lawn is enclosed and private, though a PIN is still sensible.
Noise (dB)
Also called: sound level
How loud the mower is, in decibels. Makers usually quote the sound power level, which is higher than what you hear a few metres away. Most robot mowers are quoted at about 55 to 65 dB, far quieter than a petrol mower.
Do I need it? Yes, if your neighbours are close: lower is better.
Can I skip it? Yes: differences of a few decibels hardly matter in practice.
Battery (Ah, Wh), runtime and charge time
Battery size is given in amp-hours (Ah) or watt-hours (Wh). Bigger usually means longer mowing before it goes back to charge. Runtime is minutes per charge; charge time is how long it sits on the station. The mower recharges itself and carries on, so runtime matters less than the rated area.
Do I need it? Yes, if your lawn is near the top of the mower's rated area: a bigger battery helps it keep up.
Can I skip it? Yes: don't chase the biggest battery. The rated area already allows for it, and our 5-year cost includes one replacement battery.
Area per hour (m²/h)
Also called: mowing speed, efficiency
How much lawn the mower cuts in an hour of mowing. With the rated area, it tells you how many hours a week it needs to keep up.
Do I need it? Yes, if you want the lawn finished in fewer hours, for example to keep it off the grass while children play.
Skip it if it mows while you are out anyway: the rated area already allows for its speed.
Brushless motor
A motor without the carbon brushes that wear out in older designs. It usually runs cooler, quieter and longer. Most current robot mowers use brushless motors for the blades and often for the wheels.
Do I need it? It is standard on most current mowers: not a reason to choose one over another.
Can I skip it? Yes: don't pay more for it on its own.
Charging station
Also called: docking station, base, home
Where the mower parks and charges. It needs a power socket nearby and a flat spot at the lawn edge. On wire-free mowers it is separate from any RTK reference station, though some combine them.
Do I need it? Plan where it goes before you buy: you need power within reach of the cable.
Can I skip it? Not an option: every mower has one.
Mower garage
Also called: mower house, cover
A roof over the charging station that keeps sun, leaves and bird mess off the mower.
Do I need it? Yes, if the station is in full sun or under a tree.
Can I skip it? Yes, it is optional. If you fit one on an RTK mower, check it doesn't block the satellite signal.
5-year cost
Also called: total cost of ownership
Our estimate of what a mower really costs over five years: the price, blades, electricity, one replacement battery, any wire or station kit, and any plan you need to keep it mowing. It is often a fairer comparison than the price tag. More detail.
Do I need it? Use it when two mowers look similar on price.
Can I skip it? It is an estimate with stated assumptions, so treat small differences as a tie.
Spec score
Our score out of 10, worked out from what makers publish and the same rules for every mower: navigation, 5-year cost, working without Wi-Fi, slopes, safety features and UK support. It is not a hands-on test. More detail.
Do I need it? Use it to build a shortlist, then check the details that matter for your garden.
Can I skip it? Don't treat a difference of a few tenths as meaningful.
Winter storage
Also called: winter service
Most makers recommend bringing the mower indoors from late autumn to spring, fully charged and clean, and some suggest bringing the charging station in too. Some dealers offer a winter service with new blades and a check-up. More detail.
Do I need it? Plan a dry, frost-free place for it over winter.
Can I skip it? You can skip the dealer service: you can clean a simple mower yourself.
UK warranty and EU versions
How long the maker covers faults, and who handles repairs. Some sellers list EU versions with a UK plug adapter, which may not carry UK warranty support. Separately, the Consumer Rights Act 2015 gives you rights against the retailer whatever the warranty says. More detail.
Do I need it? Always check the warranty length and that the model is a UK version from an official store or authorised dealer.
Can I skip it? Don't pay for an extended warranty without reading what it adds over your legal rights.