Three words

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As I write this, I'm sitting in the middle of  intend.agree.aware. Or alternatively, cèdre.permettre.lune.

Or, if you prefer, ambara.özüne.konuyu, or эпос.стукнуть.напрасный, or geflogen.aufhält.vollkommen, or mdogo.sokoni.yapenda, or …

What is this? and maybe more important, why?

Basically, it's a URL for the surface of the earth.

According to Fréderic Filloux, "Addressing 4 billion People in Three Words", Monday Note 11/30/2015:

Last week in New York, at the Next Billion conference organized by Quartz, Chris Sheldrick, the CEO of What3Words, captured his audience with strong arguments: 75% of the earth population, i.e. four billion people, “don’t exist” because they have no physical address. This cohort of “unaddressed” can’t open a bank account, can’t deal properly with an hospital or an administration, let alone get a delivery. This is a major impediment to global development. […]

In his previous job, Chris Sheldrick (now 33) had his epiphany when organizing large musical events around the world. Tons of material had to be shipped at a specific location and date/time. After several mishaps, he too tried using GPS coordinates to make dozens of flight cases converge at the right time and place. But people got confused with lat/long, sometimes mixing ones and sevens, etc. After a dramatic mistake that almost ruined a large wedding party in the Italian countryside, he vented his frustration to a mathematician friend who then suggested the following: why not replacing GPS coordinates with actual words that anyone can understand and memorize? Sheldrick’s mathematician pal came up with a simple idea: a combination of three words, in any language, could specify every 3 meters by 3 meters square in the world. More than enough to designate a hut in Siberia or a building doorway in Tokyo. Altogether, 40,000 words combined in triplets label 57 trillion squares.

Checking the math:  The total surface area of the earth is 4*pi*6371^2 = 510064472 square kilometers, or  about 5.101e+14 square meters. So we need about 5.101e+14/9 = 5.67e+13 labels for squares three meters on a side covering the earth's surface. The number of 3-tuples formed from 40,000 words is 40000^3 = 6.4e+13, which is about 7 trillion more than we need.

Rather than use a conventional approach to error detection, which would use a much larger space of possible word combinations, most of which would be invalid, they do this:

The what3words algorithm actively shuffles similar-sounding 3 word combinations around the world to enable both human and automated intelligent error-checking (e.g. table.chair.lamp & table.chair.lamps are on different continents).

If you enter a 3 word address slightly incorrectly and the result is still a valid what3words result, the location will be so far away from your intended area that it will be immediately obvious to the person searching or an intelligent automated error-detection system.

For more, see David Post, "Mapping the world, three words at a time", WaPo 1/12/2016, or the documentation at A "Technical Appraisal" by Robert Barr is here.

So far, no one has noticed the possibilities for a new form of geo-aleatoric poetry.

Update — Gile Rhys Jones points out that I'm wrong — many people have noticed the poetry possibilities. There's the official  what3words poetry competition, a tumblr page, a blog post by Darren Wiens, …


  1. ChrisL said,

    January 14, 2016 @ 8:10 am

    This technique is also useful for generating strong and memorable passwords, as in diceware (

    With a dictionary of 40000 words, numbers grow big very quickly indeed!

  2. Adrian Morgan said,

    January 14, 2016 @ 8:51 am

    It would be more fun if there were more words. But if I randomly string three English words together, it always comes back: "We couldn't find any results for x.y.z."

    No; no; no language.log.central; no secret.illuminati.headquarters; no I also tried a few three-word phrases that are anagrams of the coordinates it generated for my actual home address.

    I guess they designed it to be a tool or something, rather than a game.

  3. Adrian Morgan said,

    January 14, 2016 @ 9:43 am

    Update to previous comment: I found a three-word combination that works and amuses.

    I trust everyone here is familiar with SpecGram. Reflecting on the thought that they could probably come up with some good combinations to try, I typed in beware.speculative.grammar and lo, it worked. Plonked me down in remote eastern Colorado.

    Try it: (there's nothing suspicious on the satellite image, but that doesn't prove much).

    It will be interesting to see how this comment thread develops.

    [(myl) Heads up to Dave Pesetsky and Dan Everett: support.recursive.syntax is in the middle of the Atlantic Ocean, roughly halfway between Cuba and Mauretania, while oppose.recursive.syntax is in the middle of the Pacific Ocean, roughly halfway between Mexico City and Honolulu.]

  4. GH said,

    January 14, 2016 @ 10:09 am

    An ingenious and useful idea! Certainly much easier than trying to transcribe a lat-long location. I hope it is widely adopted.

    The only concern is that the mapping dictionary and algorithm should be public and standardized, not proprietary to a commercial company. (Although What3Words offers some assurances on this score, in particular pledging that the basic system will always provide a free access option, and that if the company can no longer maintain the service, they will release their code and data.)

  5. V said,

    January 14, 2016 @ 11:29 am

    This reminds me of geohashing:

  6. what3words Poetry | Darren's Side Projects said,

    January 14, 2016 @ 11:48 am

    […] This project is is mentioned in the Language Log! […]

  7. mollymooly said,

    January 14, 2016 @ 11:55 am

    Relevant xkcd orthogonal to V's xkcd:

  8. Mara K said,

    January 14, 2016 @ 12:02 pm

    Can it do addresses in non-Latin writing systems besides Russian? (Thinking especially of Chinese/Japanese/Korean.)

  9. BZ said,

    January 14, 2016 @ 1:29 pm

    People can easily deal with 10-digit phone numbers, which more than likely result in someone very close to you geographically when gotten slightly wrong, but 10-digit GPS coordinates are too hard? Heck, I have a relative in a Moscow suburb whose entire "street" address is a very large number (I forget how many digits, but at least 7). And they find him just fine.

  10. Toma said,

    January 14, 2016 @ 1:39 pm

    boring.lucid.essays is in remote Western Australia

  11. Jerry Friedman said,

    January 14, 2016 @ 1:39 pm

    Unfortunately, the picture of the college campus where I am is nowhere near good enough for me to find my office, but I'm somewhere near cucumbers.promises.remind

    Mara K.: The "change language" option doesn't offer any languages with non-Latin script except Russian. I wonder whether the question of what writing system to use for Chinese and for Japanese will be of interest at Language Log.

  12. DCBob said,

    January 14, 2016 @ 1:46 pm

    Isn't it great? I grew up in acid.tribe.dwell. How appropriate …

  13. DWalker said,

    January 14, 2016 @ 1:57 pm

    Comedian Steven Wright says that he has a full-scale map of the United States. One inch equals one inch. He lives at E-5.

  14. J. W. Brewer said,

    January 14, 2016 @ 2:11 pm

    This is so precise that my early-childhood house-plus-yard covers quite a number of 3mx3m chunks and even my own old bedroom has a couple possible addresses — it may not have been more than 9 square meters, but doesn't neatly align with their boundaries. But now of course I feel like if I reveal any of those I'll be setting myself up for some sort of weird phishing/identity-theft scam so I will confine myself to noting minerals.doodle.illogical (if not my actual nursery school classroom, at least on the right hallway of the right building) and the perhaps-apt secrets.minority.congregate (roughly approximate to the location in a wooded area where at some point in 9th grade I and a few other students sneaked off to do things we oughtn't and which we subsequently got in trouble for).

  15. J. W. Brewer said,

    January 14, 2016 @ 2:22 pm

    OK, the semantically coherent pounds.gained.bliss gets you a multi-jillion-dollar upper east side Manhattan townhouse which as of 15 years ago when I lived nearby was the residence of a by-no-means-overweight semi-celebrity (one of the ex-wives of Geraldo Rivera, I believe). But my own residence at the time can't be uniquely identified because it was in a building where there were about a dozen separate condo units stacked vertically on top of any given 3mx3m square of dirt. I guess maybe they're thinking that any part of the planet with high-rise buildings on it probably has sufficient existing unique-address infrastructure that this innovation is not what's needed?

    [(myl) For the designated purpose, floor ID should be adequate, modulo the usual problem about whether to index from 0 or from 1: so my current location is intend.agree.aware, 3rd floor (counting from 1). That's probably better than indexing meters above sea level — who knows? Google maps doesn't know that number for the floors of extant buildings, or at least can't easily be made to tell you. And a vertical (or radial) dimension relative to the local surface of the earth is problematically changeable.]

  16. Bean said,

    January 14, 2016 @ 2:35 pm

    @BZ: I don't think it's the same: phone numbers have a lot of structure to them – they are subdivided into groups – parts of them only take on a limited set of values, say, in one city, or from one telecom provider – and you memorize them and recite them the same way – and have additional information associated with them (e.g., I know he's in Dartmouth, obviously area code 902, the next part is 46-something, oh yeah, 461-, leaving you only four digits to actually get right). Whereas GPS coordinates accurate enough for this purpose don't really have the same structure. If you go with (DD MM SS, DDD MM SS) it's 13 digits plus two letters and gives you 30-ish m resolution (depending on latitude). 13 digits, even in pairs like that, is too much to remember: there's something to the old wives' tale of 7 pieces of information, I suspect.

    Ditto for the street addresses – there is structure – like in Edmonton, the house number contains information on the nearest cross street (e.g., 10457 148 St is near 104 Avenue), the apartment number is separated from the house number by a dash (305-10457 148 St.), the first digit of the apartment number indicates what floor someone is on (3rd)… it's not all memorizing for those 11 digits, there is a lot of associated information with each piece.

  17. BZ said,

    January 14, 2016 @ 3:36 pm

    My cell phone number has a different area code from landline codes at my physical location. Geographically, the closest physical location with that area code is 30 miles away, and it's been this way since I got the number (i.e. I didn't move out of the area or anything). I have people on my family plan living in the same location with a different area code. I suspect this type of thing is rather common now.

    The street address's structure only helps others find you. It doesn't help you memorize your own address. The system proposed here doesn't help others find you on the ground. They have to enter the words into some sort of system to get directions to your place, much like with GPS coordinates. In fact, the GPS has some structure, at least. With this system, there is zero structure by design. If someone calls you and says "I'm at insert.hired.code, how do I get to your place, always.friend.vivid?" You'd have no idea unless you already know where these places are (they are in fact different parts of the same shopping center, more or less).

    [(myl) In fairness, once you've identified a location, control-click in a web browser brings up a menu that includes "directions to pin", which gives you your choice of Google Maps, Bing Maps, and Citymapper. And I presume that their smartphone app (which I haven't tried) offers the same service.]

  18. BZ said,

    January 14, 2016 @ 3:49 pm

    P.S. The example in the article uses way too much precision. 34.102,-118.326 will put you close enough to Hollywood and Vine, and if you're anywhere around 34,-118, you are already pretty close (less than 30 miles) and if you can tell which way is north, you might even have a stab at which road is most likely to take you there (Westnorthwest).

  19. Chris C. said,

    January 14, 2016 @ 5:34 pm

    If I want mail delivered, I wonder if I should use the address of the square containing my mailbox, or that of my front door?

  20. J. W. Brewer said,

    January 14, 2016 @ 5:46 pm

    On further reflection for those living on an upper floor of an apartment building (or working in an upper floor of an office building etc) it seems like what would typically be most useful is not the 3×3 location directly beneath your bed or desk, but that 3×3 square corresponding to the front door (or other most-relevant-in-context street-level entrance) to the building, which in a building of any significant size is comparatively unlikely to be directly below your own particular unit. (In the multi-unit building I last lived in, the street level space directly underneath my unit was a separate commercial unit rented out as a store which had its own door to the street but there was no way to get from that store to my unit five floors above it without going back out onto the sidewalk and reentering the building through a different entrance down the block a bit.) This would then presumably need to be supplemented not merely by a floor number but by the unit/suite/whatever number using whatever conventions the actual building itself uses, which will vary semi-arbitrarily (not only could one apartment building's #7A be another's #71 or #701 etc., it's not like there's some standardized convention that #7A will always be the first unit on the right as you come out of the elevator, or the unit at the southernmost corner of the building, or any such thing).

  21. Jonathan D said,

    January 14, 2016 @ 5:54 pm

    If you enter a 3 word address slightly incorrectly and the result is still a valid what3words result, the location will be so far away from your intended area that it will be immediately obvious to the person searching or an intelligent automated error-detection system.

    Given the stories you already hear about mixups between similarly named places on different continents, that seems a bit optimistic.

  22. Tye said,

    January 14, 2016 @ 11:24 pm

    It wasn't until I read into the second paragraph of the Filloux article that I realized Victor Mair was not attending a followup session of the Next Billion conference. It sounded like a perfect call to action. We *intend* to do something about this problem. We *agree* to a course of action. We talk and write about it to make people *aware* of the issue.

  23. Tye said,

    January 14, 2016 @ 11:25 pm

    Mark Liberman. Sorry.

  24. Leslie said,

    January 14, 2016 @ 11:43 pm

    Interesting that the Turkish words aren't in their dictionary forms – özüne is öz (core, essence) + ü (possession – 'its core') + [n]e (dative – 'to its core') and konuyu is konu (topic) + [y]u (accusative). I poked around with the Russian (the only other language I know here) and didn't find anything similar – all the verbs seem to be infinitives and the adjectives masculine singular.

  25. Adrian Morgan said,

    January 15, 2016 @ 12:19 am

    Got some more … beware.ferocious.dragon is in the southern Pacific Ocean … beware.powerful.sorcerer is by the Rio Itacaiunas (river) in Brazil … dragon.eats.linguist is in Texas … or for an alternative ending, linguist.equals.hero is in Western Australia.

    Found others, but these are representative. Once you know a few valid words, it becomes easier to find more.

  26. Gregory Kusnick said,

    January 15, 2016 @ 3:47 am

    I "invented" a scheme very much like this about 20 years ago, not for GPS coords, but for computer error codes. Instead of reporting them as digit strings, I encoded them as triplets drawn from a dictionary of around 1700 short English words (enough to encode four billion distinct codes).

    I put "invented" in quotes because my employer thought the idea was clever enough to file for a patent, which was granted (and for which I was paid one dollar). So I'm curious to see what happens with this.

  27. GH said,

    January 15, 2016 @ 3:59 am

    People can easily deal with 10-digit phone numbers

    [citation needed]

    My cell phone number has a different area code from landline codes at my physical location.

    And, perhaps not coincidentally, we live in a time when most people have given up memorizing phone numbers.

    Ten-digit phone numbers were something that developed over almost a hundred years, at each step asking people to add just a couple more digits to the numbers they had to remember, according to some logical structure. If they had been a requirement from the start, the whole system would never have been adopted.

  28. Adam F said,

    January 15, 2016 @ 4:30 am

    @Chris C.
    If I want mail delivered, I wonder if I should use the address of the square containing my mailbox, or that of my front door?
    I guess you use the mailbox if you're expecting a letter or a small parcel and the front door for a big one!

  29. Adrian Morgan said,

    January 15, 2016 @ 6:16 am

    Just noticed that this …

    If you enter a 3 word address slightly incorrectly and the result is still a valid what3words result, the location will be so far away from your intended area that it will be immediately obvious to the person searching or an intelligent automated error-detection system.

    … isn't always reliable, if you are lost at sea. Compare beware.ferocious.dragon with beware.ferocious.dragons, both of which are in the southern Pacific Ocean, at almost exactly the same latitude, and with a mere 1000 km difference in longitude (my estimate). A possible explanation is that there really are dragons and it's a warning.

    (OK, from another point of view, 1000 km is a reasonable distance, comparable to that between Philadelphia and Indianapolis. But compared to the Pacific Ocean, it's not much.)

    BTW, I'd really like to see a way to convert to standard longitude and latitude. The site is incomplete without that or an equivalent. The "directions to pin" feature doesn't interest me because it requires me to give the site permission to detect my current location which isn't worth the bother, and because you can't get directions to the middle of the ocean anyway.

  30. Bean said,

    January 15, 2016 @ 7:48 am

    @BZ: yeahbut, there are still only a few area codes (aka city codes) for any geographical area where people live/work/play and might be likely to call each other, landline or otherwise. Not all 999 of them are in use in any given location, ditto for the local exchanges (the next three digits). People can retain a few of something drawn from a limited set, and it's true that the structure was "scaffolded" in over many years of phone usage (as GH pointed out).

    And I disagree, the Edmonton street addressing method also helps you memorize your own address: e.g., you move into a new condo on the 3rd floor on 148 St somewhere between 103 and 104 Ave… if you can find your own house you're a couple of digits away from memorizing the address.

    In the realm of memorizing numbers, nerds (obviously not representative of most of the population) often sit around quoting constants or conversion factors just for the hell of it (h-bar! the speed of light! permittivity of free space! radius of the earth! km to nmi! inches to cm! smoots to m!) and also to show off who's memorized more random and frequently useless stuff.

  31. Robot Therapist said,

    January 15, 2016 @ 7:55 am

    Hmm! This seems like one of those "give away personally identifying information" traps that abound on Facebook. Because I am really tempted to say "hey, I live at .." because it's moderately funny and appropriate!

    I wonder what proportion of them are, in some way, able to be seen as funny and appropriate?

  32. Adrian Morgan said,

    January 15, 2016 @ 8:13 am

    OK, I think this is the last one from me but they're just so irresistable … alien.spacecraft.crashed just south of Hawaii. (That one delights me in part because it isn't particularly remote.)

    Any further irresistable finds, I will share on Twitter (@GoldHoarder).

  33. Bmblbzzz said,

    January 15, 2016 @ 8:39 am

    GH said,
    January 15, 2016 @ 3:59 am

    People can easily deal with 10-digit phone numbers

    [citation needed]

    My cell phone number has a different area code from landline codes at my physical location.

    And, perhaps not coincidentally, we live in a time when most people have given up memorizing phone numbers.

    Ten-digit phone numbers were something that developed over almost a hundred years, at each step asking people to add just a couple more digits to the numbers they had to remember, according to some logical structure. If they had been a requirement from the start, the whole system would never have been adopted.
    The curious thing for me is that in the US – I presume that's where you are – mobile phones have area codes. By their very nature, this seems inappropriate.

  34. Bmblbzzz said,

    January 15, 2016 @ 8:42 am

    As to the scheme itself, initially I couldn't see why the squares need be so small. Then I realised the main purpose is to identify buildings (or other places) where there are no officially existing address systems, and these are often likely to be slums where buildings are inevitably small. A 3x3m square could easily cover a couple of shacks, tents or benders.

  35. James Wimberley said,

    January 15, 2016 @ 10:56 am

    oppose.prescriptive.grammar is, appropriately, in the Roaring Forties south of Cape Horn. Surely Edinburgh University could fund a fact-finding mission fro Geoffrey Pullum?

  36. Ben Zimmer said,

    January 15, 2016 @ 11:40 am

    Odd that so many rock music genres are clustered in the US… (IL) (WI) (NJ) (UT) (NC) (SC) (AK) (IL) (WI)

    But there's also… (Argentina) (China) (Australia)

  37. GH said,

    January 15, 2016 @ 12:42 pm

    I must admit to being slightly jealous of the people living by, a nice-looking house with garden in Corcoran outside of Minneapolis.

  38. James Wimberley said,

    January 15, 2016 @ 2:23 pm

    Adrian Morgan: you don't really think the Illuminati are that easy? Or that the system really maps every square? Or that the Russian codewords for the oceans are missing? There must be a special and far more comprehensive system for initiates, the way the real numbers fit between the rationals.
    BTW, secret.spy.headquarters is in the middle of a wood not far from Fort Bragg. I wouldn't check it out if I were you.

  39. Gabe Burns said,

    January 15, 2016 @ 4:40 pm

    entry.avoid.hoping, entry.avoid.hope, and enter.avoid.hoping are all in the U.S.A. and they're the first three addresses I checked.

  40. Biljana V said,

    January 15, 2016 @ 5:45 pm

    There is no secret.spy.headquarters! However is outside of Las Vegas.

  41. Roshni said,

    January 15, 2016 @ 9:07 pm

    If you look at swoons.softly.twice, you'll see part of the problem with the intended use of this system. That's my approximate guess for where a particular house in a village in India is (adjusted for finding the cutest sounding w3w address in the vicinity). I'm not helped by the fact that the entire area is badly undermapped on w3w. It's not such an off-the grid place that conventional service providers like the post office or local couriers, or repairmen can't find it. But because it's so poorly mapped on w3w, for someone looking to come to that house using that app, I'll still have to tell them, take a left at the yellow house on the main road after the school, a left again at the next four-way junction, and the house is the 2nd two-story building to your right. Or something like that (not a true set of directions, since this is public). Once we have the level of technology-diffusion where I know my exact location using w3w and all the people who are trying to find me have phones and apps that can use w3w information, we might not be that 'poorly addressed', for the benefits of w3w to be life-changing – this system may be no better than just sharing GPS co-ordinates on smarphones.

  42. tangent said,

    January 16, 2016 @ 1:45 am

    Why did they not do solid error detection? It only costs a few more bits to get 90+% detection rate. I'm guessing instead of that they optimized for the feature that people can plug in three words, see where they are, and post on the Internet…

    Maybe somebody else can do a fourth word that adds error detection.

    Did they remove homophones and other poorly-coding words?

    Errors aside, this is a reasonable way for human-human communication of a lat/long, but you ultimately need an Internet-connected device to decide it and a GPS to find it in the most optimistic case. I'm not seeing a wide window for use?

  43. tangent said,

    January 16, 2016 @ 1:53 am

    I've played this as a game, and had fun: given a lat/long on the road grid, passenger sets their GPS into "direction and distance to waypoint" mode, and then tells the driver which turns to take, trying to reach the point. No using maps of any kind, of course.

    Someone choosing the target point can make it extremely hard if they want, picking a place that can't be approached in an obvious way, so you have to drive around searching for access. Difficulty will vary greatly by city. Try it in Boston.

  44. James Wimberley said,

    January 16, 2016 @ 7:45 am

    Biljana V: You are right, secret.spy.headquarters has disappeared. I could have sworn… secret.spies.headquarters is in NE Arizona, in or near the Navajo Reservation – a holdover from the WWII Navajo talker programme? Check it before that too is suppressed.

  45. James Wimberley said,

    January 16, 2016 @ 7:52 am

    Roshni: Your "badly undermapped" criticism is true of the maps available in the website; the underlying three-words grid mapping is as comprehensive as GPS. I agree that for practical use, the developers must finalize a deal with Google Maps and other first-tier mappers. Meanwhile, I suggest trying the satellite image, which is more likely to give decent resolution.

  46. Alec said,

    January 16, 2016 @ 3:16 pm

    This is addictive! Encounter.noble.heads is in the White House, while divisions.rigid.voice is in the Senate chamber.Meanwhile, in the Canadian parliament, quietly.stars.bicker.

  47. Brian said,

    January 16, 2016 @ 4:17 pm

    @Alec: I don't know about quietly… The stars and bickering part, certainly.

  48. Jay said,

    January 16, 2016 @ 4:28 pm

    What if your address is an apartment building? Is it then "three words, #th floor"?

  49. Bruce said,

    January 17, 2016 @ 3:57 pm

    This is all fascinating. The article does make one error: the system doesn't divide the planet's surface into 3-meters on a side squares. It divides it into squares that are each 3 square meters—around 1.7 meters on a side.

    [(myl) No. The what3words site itself says "what3words is a global grid of 57 trillion 3mx3m squares". And the number of 3-square meter patches on the earth's surface is

    5.101e+14/3 = 1.700333e+14

    or 170 trillion, whereas

    5.101e+14/9 = 5.67e+13

    rounds off to 57 trillion.]

  50. aithne said,

    January 17, 2016 @ 5:20 pm

    Your UPenn address in Russian wins at poetry.

    epos-ACC clatter-PERFECTIVE-INF fruitless-ACC

    To clatter off a fruitless epos.

  51. GH said,

    January 17, 2016 @ 6:31 pm

    @ James Wimberley:

    The site uses Google Maps by default, allowing you to switch to a few other mapping services with the tab buttons. Because the system simply transforms the 3-word address to a geoposition, it can take advantage of the open APIs and embed-capability of most online map providers to integrate with any mapping system.

    The lack of map resolution in rural India is, as you say, not a problem with What3Words but with the available map services. W3W doesn't aim to create better maps, only better addressing.

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