I have created QR codes on multiple sites like I-Nigma, Kaywa and Winksite. Even though the encoded URL string is the same, these sites create different looking QR codes. On further research, I found that this has to do something with the ECC level. Does anybody know what ECC level I-Nigma uses to create codes.
I created an Qr code on http://qr.tugraz.at as reference and one with the same content with i-nigma.com. The codes look equal if I choose the error correction level M.
I am curious, why you would like to know that :)
The reason, why you are getting different results on various websites is, that different declarations for the content are used. E.g. i-nigma adds "URL:" in front of the http.
The QR Code Generator at www.qurify.com has an advanced generator and also the posibility to print your Codes at once on one page. Maybe you can compare different prints this way.