SeedQR is a clever way of transforming your seed phrases into a single stream of digits
Just to extend a bit your statement.
There are two formats of SeedQR: Standard SeedQR and CompactSeedQR. The first one transforms seed phrases into decimal digits stream while the second into stream of binaries.
Whatever is the flavor of SeedQR, the online relevant readers must never be used to transform them into SEEDs.