QR Code Model 1 vs Model 2: What Changed in the Original Standard

1. Two Generations

Model 1 is the original 1994 symbol. It reaches up to Version 14 (73x73 modules) and about 1,167 numeric characters. Model 2 is the enhanced version, extending to Version 40 (177x177) and adding alignment patterns that help decoders cope with distortion in larger symbols.

2. Why It Matters Today

Virtually every generator and phone produces and reads Model 2. Model 1 survives mainly in legacy industrial systems. The model is signaled in the format area, so readers distinguish them automatically.

3. Practical Advice

Unless you are maintaining a legacy factory scanner setup, always generate Model 2. If an old reader cannot scan your code, check whether it supports Model 2 and its larger versions.