QR code too small or blurry: why it happens and how to fix it

Small and blurry are two different failures with overlapping causes. Work out which one you have.

Is it blurry or just small?

Look closely at the printed code. If the edges of the squares are soft or jagged, it is blurry. If the squares are crisp but tiny, it is small. Both can be true.

Blurry, cause 1: an upscaled bitmap

A 200 px PNG stretched to 8 cm has 25 pixels per centimetre. Every module edge is interpolated into a grey smear. Vector formats have no pixels.

Fix: re-export as SVG or PDF, or as PNG at 300 pixels per inch of the final size. See export formats.

Blurry, cause 2: modules smaller than the printer can hold

Ink spreads. Below about 0.5 mm per module, adjacent squares bleed together. Office printers and receipt printers are worst; commercial litho is best.

Fix: shorten the content so the version drops, or print larger. The size calculator shows module size for any combination.

Blurry, cause 3: JPEG

JPEG compression blurs sharp edges by design. Never export a QR code as JPEG.

Small, cause 1: designed for the wrong distance

A code that is fine on a leaflet at 40 cm is invisible on a poster at 3 m. Minimum size is the scan distance divided by ten. The size guide has the table.

Small, cause 2: the long URL again

A long URL forces a high version, and a high version at a fixed printed size means tiny modules. This is the single most common root cause of both small and blurry codes.

Fix: use a short link, a dynamic code, or drop the tracking parameters. Dynamic codes track scans without them.

Checklist

• Exported as SVG or PDF, or PNG at 300 DPI of final size
• Not JPEG
• Module size above 0.5 mm, checked with the calculator
• Content shortened; version 6 or below for small prints
• Size at least the scan distance divided by ten
• Test sheet printed on the final stock