Dynamic and static codes, and why it cannot be undone
The single decision that matters most, made before you download and irreversible once the code is printed. It is worth two minutes.
A static code contains your link
The destination is encoded in the pattern of the squares. Scanning it never touches our servers or anybody else's — the phone reads the URL straight out of the image and goes there.
That makes it permanent in both senses. It will work in ten years whether we exist or not, and it can never be changed by anyone, including you, including us. If the destination dies, the code dies with it.
It also cannot be measured. There is no request to count, so a static code produces no analytics at all.
A dynamic code contains a short address
The pattern encodes a short address that resolves through us and forwards to wherever you have currently pointed it. Change the destination whenever you like; the printed square is untouched.
Because the request passes through, it can be counted — which is where every report in the product comes from.
How to choose
If the destination will never change and you do not need to measure anything — a Wi-Fi password, a phone number, a permanent reference document — static is simpler and depends on nobody.
For anything promotional, anything printed in quantity, and anything you will want to report on, dynamic. The cost of guessing wrong is asymmetric: a dynamic code you never repoint cost you nothing, and a static code you needed to repoint costs a reprint.
It cannot be converted afterwards
The two kinds encode different data, so the printed symbols are physically different. Converting one to the other means a new code and new artwork. The studio tells you which one you are making before you download it, for exactly this reason.