QR Codes Restrictions

Question

I need to generate codes with custom fields: id of field+name of field+values field.

• How long can I encode in a QR code? I need to know how many fields / values ​​I can insert.

• Should I use XML or JSON or CSV? What is the most common and effective?

Answer 1

XML / JSON will not qualify for the alphanumeric mode of the QR code, as it will contain lowercase letters. You will have to use byte mode. The maximum value is 2,953 characters. But the practical limit is much less - perhaps a few hundred characters.

It is best to encode a data hyperlink if you can.

As Terence says, no reader can do anything with XML / JSON except to show it. In any case, you need a custom reader to do something useful with this data. (This suggests that it is not very useful for QR codes.) But if you create your own reader, you can use gzip compression to make the payload much less. Your reader will know how to unzip it.

You can leave with something workable, but overall this is not a very good approach.

Answer 2

The maximum number of alphanumeric characters you can get is 4,296 . Although this will require the lowest form of error correction and will be very difficult to scan.

JSON is generally more efficient at storing data than XML.

However, you will need to write your own application to scan the code - I do not know any that will process raw JSON or XML. All scanners will show you text.