What's the simplest and quickest free way to convert W3W back to trad OS with a browser? I don't want any smartphone app. An http API would be great where you could visit say W3W2OS.co.uk/sixfigure/aced.zooms.steadier and get SN104456 back as text.
I've banned the use of W3W in my company but clients (almost all are in the UK) seem to love it and so the first thing we have to do is convert their W3W into the OS system and politely make sure that they never see W3W again in documentation. We avoid lat-long too because it is both inconvenient being in degrees, mixing up positive with negative numbers, and error prone through its sheer verbosity.
The OS system is simple, succinct, readable and mathematically intuitive for UK purposes: for example SN123456 is obviously "fairly near" SN104456 since we are in units of 100m, and it's obviously in Mid/West Wales if you live here and know what the SN square roughly covers. I live in SO, so I know straightaway that SN is ballpark 100kms/60miles away from home, or at worst 140kms along a map diagonal. Just compare that to 52.07708737136622,-4.767253634197883 or aced.zooms.steadier for clarity and usability.