Question 1

Which error correction level should I choose?

Accepted Answer

Use Level L for clean digital displays where damage is unlikely (smallest code). Use Level M for general-purpose printing. Choose Level Q or H when the code will be printed on packaging, outdoor signs, or when you plan to overlay a logo on the code — the higher redundancy lets scanners read the code even with 25-30% obscured.

Question 2

Is there a maximum data size for QR codes?

Accepted Answer

The largest QR code (Version 40, Level L) can store 7,089 numeric characters, 4,296 alphanumeric characters, or 2,953 bytes. In practice, keeping content under ~300 characters ensures fast scanning on all devices. For long URLs, use a URL shortener first.