How to estimate a QR code redunduncy level?

Question

I'm not a specialist, but as far as I know, a bit of information in a QR-code is coded more than once, and it is defined as the redundancy level

How can I estimate a QR-code redundancy level ? Is where an mobile app or a website where I can test my QR-code redundancy level easily ? If not, is it an easy algorithm that I can implement ?

Redundancy is sorted in different categories according to this website, but I'd like to have the direct percentage value if possible

Answer 1

There are some pixels next to the lower left positioning block which indicate the redundancy level. Quote from https://blog.qrstuff.com/2011/12/14/qr-code-error-correction

Quite conveniently, there’s also 2 modules down in the bottom left-hand corner of every QR code that display what the error correction level used in that QR code is.

There is a very nice graphic on that page which visualizes this, which I won't include here as I assume that I'm not licensed to do so.