Are QR codes guaranteed to work?

Not sure if this will get closed as "not a real question" but I asked this on Superuser and it was closed for that very reason. We are thinking of implementing a QR code which will be sent to a number of users via a letter.

Now I'm aware that you can just Google 'QR codes' and there are a plethora of options that allow you to make a QR code. My question is thus; if we do go with this solution can we guara开发者_如何转开发ntee that it would work cross platform? I.e. on Android, iOS, Symbian etc? Once a QR code is generated will it work on ANY app on ANY platform?

Thanks and apologies if this is not really a 'programming question'

Thanks

Kiran

The only time I have had problems is when the resolution of the screen displaying/the printer that printed the QR code was too low. Ensure that your QR code is big enough for the data its holding and you should be ok.

I found if I padded out the data in my QRCode with spaces or zeros I could maintain a set size which helped me place it on a page and always know its size.

Kind of a suck it and see problem though

Edit

PS. Don't use QRCodes for the sake of using QRCodes - if you're sending the user the QRCode by email why not just send them a hyperlink?!

There are QR code readers for all platforms. It is a well-established ISO standard. Whether its content will be interpreted how you want is a bit more platform-dependent; the QR code spec says nothing about what to do with the content.

However, if you're just putting text or URLs in a QR code, it will certainly be handled as you expect on all known platforms. It might be more hit and miss if encoding stuff like vCard data.

See this guide to QR code contents.