Update 11/2021: Clarified some statement due to the comments of the w3w’s “Chief Marketing (!) Officer”.
There have been many requests if the GC Wizard could also support the coordinate system what3words (w3w). Here are our three words:
What is what3words?
w3w is a system developed by a company for addressing the world in a simple way. For this purpose they divided the world into a 3x3m grid. Each square is now assigned to three pronounceable words. If you need a location or an address somewhere in the world, no endless columns of numbers or complicated address schemes have to be transmitted, but only these three words. On the company’s website you can then look up where these three words point at. This is intended to simplify communication for, e.g., emergency services or just to provide structurally weaker areas with the possibility of general addressing.
How does what3words work?
w3w provides a server on the internet. On this server is the database with a list where each group of three words is assigned to a specific coordinate. This list is not publicly visible, but only accessible via the connection to the website.
Well, the word groups are not (only) calculated using a machine algorithm, but also on the basis of various factors that are strongly human influenced, such as similar pronunciations of different words or different spellings/spelling mistakes of certain words. This is to avoid that similar word combinations are too close to each other, and, therefore, to avoid misunderstandings on transmitting e.g. to a postal or rescue service. On the other hand, this also leads to the fact that this list cannot be easily reconstructed, because one does not know the human factors in detail.
So, what’s the problem?
There’s a technical and a – let’s say – political one.
The technical problem is simple: If you knew the word lists, they would be very, very large. Dividing the world into 3x3m squares results in 57 trillion (!) squares (Source: Wikipedia). Even with various optimizations, this number results in a huge memory capacity. This is not an option for a mobile device at the moment and at least not in the mid-term future. Different languages not yet included.
Now you could simply provide an online connection to the interface, as other tools already do. But this contradicts the idea that GCWizard should be a pure offline tool and should work even in the farthest Mongolia without any internet connection (map views are the famous exception from this, of course). This would not be possible here anymore, because a internet access to the website of the company would be absolutely necessary. (Update 11/2021: According to the comments of w3w, there’s a offline option. However, it is not clear whether it works with our chosen programming framework Flutter/Dart and it would increase the entire app size by at least factor 2. And there’s still the political problem…)
But even if one were to make an exception, there would still be the political problem:
w3w is a closed, non-free, commercial system (
which in my opinion already contradicts the declared goal of being available to aid organisations Update 11/2021: According to the w3w comment, the usage for NGOs, emergency and “charity” is for free). Even more: It is patented. The company behind it uses this to completely prevent any similar development. For example, there was the WhatFreeWords project, which rebuild the system as a free open source project. This project was legally prosecuted by the company and its consequence was forbidden.
In our opinion, such a business model is not compatible with the demands of an OpenSource project. That’s why we don’t want to support this company with an integration into GCWizard, which, in fact, is an OpenSource project.
And so – even if it is requested for understandable reasons – w3w will not be part of the GCW as long as I have my fingers in the pie.
Translated with help of www.DeepL.com/Translator (free version)
Hi, to clarify the technical point: what3words is available as an API. By using our SDK, what3words can also be built into any device to work offline. As it is an algorithm the size is small and all of our 46 languages are available. I work at what3words.
thanks you for your statement.
Could you please tell me how the SDK works? You stated, that there’s an algorithm which can be embedded. How does it work? Does it really generate the three words without any additional information from your database (so I have to correct my text)? Or does it store a local copy of a wordlist/database on the device (if so, how large is the file)?
Is it available for Dart?
Can I use it for free (A quick look at your website lists the SDK under an Enterprise Suite)?
Nevertheless, it remains closed source, right?
The SDK includes the algorithm that contains the word list. It takes the GPS coordinates and generates the three word address offline. There is no need for a data connection.
The SDK in in the 10s of MBs. Depending on the number of languages included. What3Words is currently in 50 languages.
Yes what3words is proprietary. What3Words changes business who can make or save money to access the system in the same way any geocoding system does. It is available for free for emergency services, NGO and charities.
as far as I understand, what3words
– supports flutter and dart:
– offers two API Plans:
+ a free one with
– 1.000 convert to coordinates request per month plus
– unlimited requests for converting to 3 word addresses
+ a business plan starting at $45 per month.
Here is my suggestion:
– we provide the functionalities
– the user request an API-key which will be set in the setting.
– Hence every user is responsible on his own