I recently discovered that the search engine DuckDuckGo generates a QR code for a query that begins with “qr” (it has been doing this since 2013).

DuckDuckGo QR demo

By the way, in addition to the plain text in the QR code can be written:

  • Wi-Fi network data, including password (look for QR code on your modem): WIFI:T:WPA;S:mynetwork;P:mypass;,
  • geolocation: geo:40.71872,-73.98905,100,
  • events (name, start and end dates and times)
  • malicious link,
  • as well as many other things.

More information is collected here: https://github.com/zxing/zxing/wiki/Barcode-Contents

There are several QR code libraries for the Go programming language, and I used this one: https://github.com/liyue201/goqr