A Critical Analysis of the What3Words Geocoding Algorithm

Rudy Arthur takes an academic look at the problems behind W3W – https://arxiv.org/pdf/2308.16025

It concludes:

“Contrary to what W3W claim, this work has shown that many confusable W3W addresses
are likely to exist and has identified some serious problems with the W3W algorithm […] I would caution against the widespread adoption of W3W […] W3W should not be adopted as critical infrastructure”

W3W Wastes Air Ambulance Money with Mountain Rescue Error

“Initial information via W3W, gave the casualties location on Big Moor. We were suspicious of the integrity of the location, as the incident was reported at a bridge and not in the middle of the moor.

“After a fly over by Derbyshire, Leicestershire & Rutland Air Ambulance Helimed 54, no one could be seen. Further investigations and with the help of Phonefind technology, the new position showed her at the Packhorse bridge in South Burbage.

“All resources quickly relocated to South Burbage where the casualty and friend were rapidly located.”


What3Words sent a legal threat to a security researcher for sharing an open-source alternative

But the company can’t point to a single case of copyright infringement

Aaron Toponce, a systems administrator at XMission, received a letter on Thursday from London-based law firm JA Kemp representing What3Words, requesting that he delete tweets related to the open-source alternative, WhatFreeWords. The letter also demands that he disclose to the law firm the identity of the person or people with whom he had shared a copy of the software, agree that he would not make any further copies of the software and to delete any copies of the software he had in his possession.

Why we don’t use What 3 Words


Twisted your ankle on a fell and need help and want to know your What 3 Words location so you can pass this on to emergency services? Well, for a start do you have a mobile phone? Is it working or did you break it when you fell over? Has it still got charge or is the battery flat? Assuming it is working do you have a data connection? And if you do are the What 3 Words servers online?

W3W leads emergency services astray

A couple came across a lone walker who had slipped and suffered a suspected ankle fracture. They managed to contact the police, asked for mountain rescue, and provided a What3Words location. They then stayed with the casualty until the rescue team arrived. For some unknown reason the W3W reference positioned the casualty close to the A66 near Braithwaite. Fortunately PhoneFind technology was used and a grid reference confirmed the location as on a path between Green Gable and Base Brown – many miles from the A66!