# What advantage does the what3words coordinate system have over other, traditional systems?

I recently came across the what3words coordinate system in an outdoor magazine. The system divides the world into squares of 3 m x 3 m. Each square is then named with a combination of three (as far as I understand) arbitrary words, but each three word combination denotes a specific square. Buckingham Palace entrance in London for example is fence.gross.bats. The magazine described the idea as revolutionary and that it will probably make a big impact.

The trouble is: I do not get the point. For what purpose is this system really useful? Are there specific cases in which it is superior to, let´s say the geographic coordinate system? If you use a (latitude,longitude) combination of decimal degrees with six decimal places like (51.501381,-0.141830) and enter them into one of the known map services, you will have an accuracy of approx. 1 m on the latitude (distance of 111km between two lines of latitude divided by 106) and an even better accuracy on the longitude. So accuracy cannot be the point.

The only advantage I can think of is that three words are a bit easier to memorize than a combination of numbers. Do I miss a point? Has anybody used the what3words system seriously, i.e. not only played around with it?

• It is an advantage to the for profit company, the more people use it the more money they make. en.wikipedia.org/wiki/What3words#Criticism Jan 14, 2020 at 13:52
• I see this pretty much the same as you, and note that lat&long (or your local grid system) doesn't need an internet connection if you've got a paper or electronic map. They claim the words are unlikely to be confused with other combinations and thus are clearer to transmit for the uninitiated. I'm not sure how useful that is in practice Jan 14, 2020 at 15:35
• If you're interested in alternate location identifications my favorite is: en.wikipedia.org/wiki/Open_Location_Code I don't like what3words because just knowing three words doesn't help you. You need to lookup the words in their proprietary database. Nearby places don't use similar words. A personal requirement is that you should be able to just use a map/globe to find a location without a huge proprietary reference database. Jan 14, 2020 at 21:52
• @182764125216 Open Location Codes have been used by a charitable organization to make address plates to affix to the front doors of people who never had an address before in some cities in India. The algorithm to convert a code to/from long/lat is so simple that anyone can include it in mapping software, with no database required. Jan 14, 2020 at 23:50
• Related: travel.stackexchange.com/questions/144190/… But I agree with @182764125216: Open Location Codes (also known as Plus Codes, and available in Google Maps) are IMHO a far better alternative. Jan 15, 2020 at 12:02

They don't really pitch it as a replacement for lat/long, but more postcodes and street addresses. A building number and postcode can (and has, IME) have an entrance on a different street, under a flyover, or any number of ways that make it difficult to actually find the entrance to a building. W3W can target a building entrance or location that doesn't have a street address fairly accurately.

However, I think you are right to be sceptical.

Pros

• Ease of remembering certain locations.
• Shorter values (three words to mark a 3mx3m square, which for most applications is more than adequate), as opposed to lengthy lat and long numbers. Particularly as longer words are reserved for squares that will be used less, such as over the ocean.
• Makes sharing locations over, for example, poor quality phone lines more reliable (possibly).
• Useful where street names aren’t really used or in areas where a single postcode can cover a large area.

Cons

• The algorithm is closed source and whilst the developers promise not to game the system (such as sponsorship deals to change the words used to identify a corporate HQ to something relevant to that company - e.g. Ford's HQ being identified by `cool.motor.cars`) a promise really isn't worth anything IMO.
• Licensing costs for car manufacturers etc to put the technology in their products.
• Doesn't work with altitude, although to be fair, neither does lat and long without adding a height vector.
• Current systems (GPS, lat/long, zip & post codes) are so ubiquitous that I can't see this system becoming universally adopted.
• It is non-hierarchical. That is; there is no connection between the words used in adjacent squares and only knowing two words of a square will not allow you to get a rough idea of its location in the say that knowing a town name but not a street name would at least give you an approximate location, or the first few significant figures of a longer coordinate address like a lat/long.
• Can only be used electronically. You can't get your W3W location from a paper map, which should be an important backup option for anyone interested in the outdoors. Offline use is possible but needs to be planned for and downloaded in advance if in a poor signal area.
• No correspondence between different language versions. That is; my location in English wouldn't make sense to someone using the system in a different language.

Following recent criticism from mountain rescue services, I thought I’d add this:

• Mountain rescue teams have been provided wrong locations due to words being slightly misheard or misreported when passed along the chain of rescuee, call operators and emergency services. Whilst in many cases they are obviously wrong as they are located in other countries, a study by Pen Test Partners found that

W3W often gave similar-sounding words and plural versions of words for locations in close proximity, which could cause confusion. So, for example, circle.goal.leader and circle.goals.leader are less than 1.2 miles (2km) apart along the River Thames.

And

Something like 73% of What3Words addresses contain a word that can be changed just by adding or removing a letter.

This gives a lot of potential for the rescue teams to be unwittingly sent to the wrong location and putting people’s lives at risk due to delays.

However, anecdotally, as someone who has recently had to be rescued themselves from a remote location where two crews attended; one spent some time searching for us as they hadn’t been given the w3w location and the other one came straight to us because they had. On the whole, I’d rather pass on both the w3w and some other location data, such as lat & long, so the location can be verified.

• Comments are not for extended discussion; this conversation has been moved to chat. Jan 17, 2020 at 9:50
• Actually the 3x3m together with non-hierachical is also a disadvantage. I was trying to find my 3 words for my apartement. But technically each room would have different 3 words. So I gave up. Jan 17, 2020 at 12:02
• @lalala - That is one of the unmentioned advantages. Your apartment (and any other address) will have multiple, equally valid What3Word addresses, so you can pick the one that is easiest for you to remember. Jan 17, 2020 at 15:49
• @PaulSmith that is indeed an advantage and a disadvantage. Suppose I was a pizza delivery company? is there an easy way to figure out a certain what3words address is near a known deadbeat? Jan 17, 2020 at 20:03
• @emory No because the system is non-hierachical. There is no relation between all physical doors on a street as far as W3W goes. Jan 21, 2020 at 14:08

Another use of What3words are outdoor scavenger hunts or geocaching riddles.

It is much easier to make riddles that have certain words as a solution rather than numbers. You can use it for a children/teenager birthday partys, where they need to solve riddles and the 3 words are pointing to the place where the next riddle is hidden.

You use What3words when you are looking for convenience rather than accuracy. Let's say if you are in an emergency situation and you need police assistance. It is much faster to let the police know your current location by saying fence.gross.bats rather than a bunch of numbers, (51.501381,-0.141830), for example.

• There is an element of accuracy here as well, accuracy of the transmission -- it's much easier to read off and confirm a set of three words without mistakes, while surrounded by a lot of ambient noise; than to try to do the same with GPS coordinates. I remember reading an article about the originator of what3words -- he is (or was) a musical concert organizer, and he once sent one of the musicians haring off to another part of Italy from the concert location, because of a mistake in one of the GPS digits. Jan 15, 2020 at 7:49
• @ZevSpitz I disagree and think that numbers are more easily verifiable without mistakes. There are ten numbers, each of which has a distinctive sound; as opposed to thousands of potential words, each of which could sound like another one. To use the example from the answer: did you say "fence.gross.bats" or "dense.most.cats"? Or was it "lens.coast.gnats"? Jan 15, 2020 at 9:57
• @AaronF `fence.gross.bats` is in London, but `fenced.gross.bats` is Mudanjiang in north-east China, near the borders with Russia and Korea. And `fends.grows.baths` is in Quebec... Jan 15, 2020 at 11:38
• @AaronF But you have to transmit 16 numbers correctly, you only need to transmit 3 words correctly. It's much easier to verify and repeat/read back and it also fits into human short term memory much more easily. Jan 15, 2020 at 12:03
• @TimB Even if you transmit a W3W location letter-by-letter, it seems that it will typically be about the same number of characters as GPS coordinates, and it has the advantage of predictable letter patterns. Each digit of a GPS coordinate has no bearing on the previous or next digit, so there's no indication if you get a digit wrong. With W3W, if you get 16 characters that don't form 3 words, it's obvious that there is an error somewhere. Jan 15, 2020 at 14:58

It's a stupid system, even without looking at it. I don't see it as having any advantages.

• You have to deal with homophones. Their.bare.deer and There.bear.dear.

• If it's universal, you have to deal with all interlanguage homophones, Si in Spanish, Sea, and see in english, ci in French.

• Spoken language carries a lot of information by context. Try to transcribe random words. In normal language the context of the word before gives you information about what word to expect next. If you have ever had a radio conversation over a noisy channel, you find that a single idiom or allusion in your speech can side track the whole coversation. If you have ever had a conversation, not understood a phrase, then replayed in your head to use the words after to "reconstruct" what was said you will get an idea of what I'm talking about.

• Written language has it's own pitfalls. Are you going to limit your system to ascii characaters only? Do other nations have to give up all their diacritical markings on letters? Do all asians know latin lettering?

The net result will be that you are going to have to spell it out phonetically, or send it as a text string to anyone who needs an accurate transcription.

I don't take my phone with me in the back country. There's no reception. How do I find out the code I'm in.

Like the phone system, it tries to avoid having neighbouring zones having similar coordinates (area code/words)

The conventional coordinate systems at least are tolerant of certain errors. Degrees to 4 or 5 decimal places locate you close enough to hit with a pine cone, and if you are going on a conventional outing, your base people know where you are to some fairly close degree. The whole idea of UTM is that 6 digits gets you to within a football field -- if the person at the other end knows where you are to within 100 km first.

How many of the rescue agencies use it now? So you have a delay while they turn Electric.Ambling.Hippos into a lat/long set of coordinates on some web page. This can be a serious delay, as the helicopter base station doesn't have cell reception either. And just hope that someone writing this down didn't put down Erection.Rambling.zippos which is over in East Horsebiscuit, South Dakota.

I used UTM grid once to report an accident. My GPS was set to that to work with the topo maps I was carrying. Those maps have a UTM grid but lat/long only on the edges. UTM is much more useful on the ground. Turns out the chopper pilot only could work with lat/long. That's what his device read. Cost me an extra 20 minutes wait, EVEN THOUGH HE HAD THE EXACT SAME PAPER MAP I DID. Didn't cause extra grief. Boy had a torn knee ligament.

I do have an InReach. Push the "HELP" button, and my coordinates are on their way to my designated contact. If you have a SPOT it works the same way. If you have a PLB, turn it on.

When I'm the back country, I set up a list of checkpoints. I leave a copy of my maps with the checkpoints with my contact in civilization. Daily I send back both the lat/long but also my text location relative to the nearest check point. (2 Km East checkpoint 6A) to give some degree of error checking if someone doesn't transcribe the coordinates correctly.

As a nav aid in what passes for civilization, I can use my phone to send a pin. If I phone 911, my location goes with that call.

As a game aid, make up your own.

I ran a ROGAINE style program for 6 years. I had 1300 controls scattered out over 200 km2 of territory, each with an alpha numeric ID and a code word. Clues had the ID, Finding the control with the same ID showed you found the right one. Returning the code word showed you'd actually been there.

• This is the real problem with it--as a backcountry tool I see it having value, but it doesn't work in the backcountry because it needs web access. Jan 21, 2020 at 15:46

This is used a lot by emergency services, in fact I've recently seen emergency services advice recommending people install it on their phones.

If you are outside, in the wind and the rain, and someone's had an accident and you're by the side of a road or half way up a mountain or anywhere else where you can be unsure of your location or how to share it then what3words gives you a clear and accurate way to share your location.

It's much simpler for someone not used to co-ordinates to read off three words than it is to find and then read out their latitude and longitude. It also doesn't rely on having a data service once the app is installed, so you can write down the 3 words, move to a place where you have signal then request help directly to where it is needed.

It's also much more reliable. A long string of numbers is easy to get one wrong, or mishear one, or have to repeat several times. 3 words are 3 words.

https://www.bbc.co.uk/news/uk-england-49319760

South Yorkshire Police used it to find a 65-year-old man who became trapped after falling down a railway embankment in Sheffield.

North Yorkshire Fire and Rescue Service found a woman who had crashed her car but was unsure where she was.

And Humberside Police were able to quickly resolve a hostage situation after the victim was able to tell officers exactly where she was being held.

"That was a time critical situation and being able to use a three word address meant officers could get there much quicker, rescue the hostage and arrest a man," Mr Sheldrick said.

"That made us understand how the work we are doing is so important."

• Around here, they simply trace cellphones.
– Mast
Jan 15, 2020 at 13:33
• @Mast: Tracing the phone is simply not accurate enough. It only puts the caller within range of a mast, which in the countryside could be an area of tens of square miles. Jan 15, 2020 at 13:45
• @Chenmunka your comment is usually wrong. That's only true if there's only 1 mast in range. Multiple masts have allowed triangulation for years, and they don't have to be from the same provider. With a data signal it's even better - after a bike crash the ambulance service sent a link to get my location, and that was the fallback because I was roaming abroad and the primary system didn't work. (I knew exactly where I was, but the road name wasn't on their system; this method was simpler than me getting lat+long, which I could have done) Jan 15, 2020 at 14:10
• @ChrisH That link probably used your phone's GPS. It is possible to triangulate based on phone signals but last I heard the process is not particularly fast or accurate/reliable. Jan 15, 2020 at 14:59
• @TimB the link definitely did (or hybrid GPS+network), and my GPS was already running so it was instant.. Triangulation can be pretty good though. Jan 15, 2020 at 16:05