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Migrating an application from API V2 to API V3


The what3words API has been updated to V3 with the benefits of a simplified interface and new functionality.

AutoSuggest has been greatly simplified and now features powerful new country clipping. Error handling has been improved for v3, making it easier and more robust to use v3.

With the release of V3 of the what3words API, V2 of the API is now officially deprecated, though V2 and V3 will continue to run in parallel for some time.


Resource names

To bring consistency to our function names across all our offline SDKs and our online API, the v2 API resource names have changed in v3, as follows:

  • forward is now convert-to-coordinates
  • reverse is now convert-to-3wa
  • grid is now grid-section
  • languages is now available-languages
  • autosuggest, voice-autosuggest, standardblend and voice-standardblend has been greatly simplified and combined into one v3 function: autosuggest

In many cases, the parameters have changed. Please refer to the v3 API Reference Docs.



The Standardblend resource has been removed but the functionality can be easily replicated within the unified autosuggest function.

To implement in v3 call autosuggest with n-focus-results=1. This replicates the V2 standardblend behaviour, which was to have one focussed result, and the rest unfocussed.


API response formats

By default, V2 of the API returns a payload in JSON; optional format types of GeoJSON is also supported. Due to low usage, JSONP and XML are no longer supported.


HTTP status codes and API error codes

V3 of the API now uses appropriate HTTP status code. It returns a 200 on success. For more details see here.

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