Reference library
QR code guides
Everything worth knowing about the format, written by people who print these for a living rather than people optimising for a keyword.
Written from production, not from other websites
Most QR code advice online is copied between sites, and the copying propagates errors. Figures for capacity disagree with the specification. Minimum sizes get quoted with no reference to module size, which is the number that actually decides whether a code scans. Scan statistics circulate with no traceable source.
These guides take a different approach. Technical claims are checked against ISO/IEC 18004 or derived by testing a reference encoder, and where something depends on a device or a press we say so rather than giving a false single answer. Where we do not know, the page says that too.
They are written for people who have to make something work in the physical world — a menu that scans in dim restaurant lighting, a label that survives a warehouse, a board read from across a garden.
Three routes through the material
- Printing something soon? Read the sizing guide first, then error correction. Those two cover most failures before they happen.
- Something already broken? Go to the failure diagnosis guide. The causes are ordered by how often each turns out to be responsible.
- Want to understand the format? Start with what a QR code is, then how they work, which covers masking and Reed–Solomon correction.
- Worried about safety? The quishing guide explains what a code can and cannot do to a phone, and how to check one in ten seconds.
Getting it onto paper correctly
Safety, permanence and reference data
Frequently asked
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Last reviewed 24 August 2026 · Checked by the QR Code Builder team