Fixing What3Words?

There are an awful lot of people saying that fixing the issues with What3Words is “simple”: just remove the plurals! Get people to read it out twice! Spell the words!

This shows that people haven’t understood the problem fully, or looked at the other issues What3Words has.

What problem are we trying to solve?

What3Words, according to Wikipedia, was created for communicating locations, but there’s nothing saying it was for emergency services.

The system may be fine to use where the cost of making mistakes is low, when people aren’t under pressure, or when entering your location for a takeaway delivery.

That doesn’t mean it’s fine for emergency use. It doesn’t mean it’s fine for use in mountains.

Without clearly stating the problem, it’s very difficult to come up with a solution.

It’s not even clear that the problem is “verbal communication of location”. With the advent of smart phones and always on data connections, why are we using voice?

Why try and fix it?

People keep on comparing What3Words to lat/lon, saying that it’s clearly better. I can’t see any evidence around this. I kind of like evidence in safety critical applications.

But why not use a better system than What3Words?

There are many alternatives available that could be significantly better. I can’t see any studies or data comparing the available systems.

Another similar word based solution could be better. Take a step back before trying to fix a broken solution. Working within the constraints that exist with the current system will likley result in a suboptimal solution.

Just change the word list…

As a result of using 3 words and 5.7e13 locations, a word list of 40,000 long was needed.

This means it contains words like:


Removing over 7000 plural words will make this list even more complex as you replace the words.

In my opinion, it’s already at the point where it would be difficult to use by people who are not excellent at reading and spelling. It’s certainly less usable for children – the age at which a child can read out letters and numbers is earlier than they can spell trosseau.

The algorithm has issues

Features of the algorithm mean that there are closely linked areas that have lots of addresses with 2 common words in them. Even if you fix the word list, this issue still exists.

With this issue still present, it is far more likely that a mistake in one word results in another close location.

Other errors can be made

There are not only plurals. There are homophones, missing letters, adding letters, transposition… all of these should be fixed, no?

Why 3 Words?

There’s no evidence that 3 words is a good or optimal solution.

If you used 4 words, the dictionary size drops to 2748. It’s a lot easier to avoid complex words and plurals with a list this short.

They said they wouldn’t change the addresses

In many locations they say they won’t change the addresses. That means the wordlist and algorithm can’t change.

People have made lots of signs using locations.

It’s offline

The What3Words algorithm is meant to work offline. It’s in dashcams, car navigation systems. You can’t quickly and easily update them all. Which leads to…

And there’s no versioning

If they make significant changes, there’s no versioning system. Incompatible systems could lead to massive issues.


5 thoughts on “Fixing What3Words?

  1. Permalink  ⋅ Reply

    Jeremy GH

    May 1, 2021 at 1:52am

    A further complication with w3w arises – as I see it – from the way the way they have implemented multilingualism – each language has its own wordlist and variant of the algorithm. There are now 48 languages (and counting) – about half using the latin alphabet, 25000 words each, so 600,000 latin alphabet words required. So you find words like ache, hake, shake, spake which are used – but not in english w3w – even if they are english. But available for misrecognition… (can you easily distinguish bahn.bahn.bahn from barn.barn.barn?). I think there is a limit of two languages possible for the app (web interface seems to be able to take them all – good luck with non-latin script ones) – do controllers take what comes, or know how to explain how to change one of the languages?

  2. Permalink  ⋅ Reply

    Merton Hale

    May 1, 2021 at 9:24am

    I have developed and patented a location encoding technology that I feel is far superior to What3words. It uses 6 or 7 character alphanumeric codes. Every address is assigned its own unique code. Think of it as every address as having its own unique postal code.
    Example: LN-ABC23 for an address in London; NY-25ADF for an address in New York.
    Take a look and let me know what you think.

  3. Permalink  ⋅ Reply

    Merton Hale

    May 3, 2021 at 9:43am

    Both Apple and Android phones have built in systems to enable user to quickly txt their location to emergency services. This is far superior to downloading W3W app, etc. I feel W3W is doing a disservice to people by pushing their app oveer much better methods already available.

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