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QR Code Size, Error Correction & Print Guide (2026)

·7 min read

A QR code that doesn't scan is worse than no QR code at all — you've asked the user to try, and delivered a broken experience. This guide covers the two things that determine whether a QR code will actually scan in the real world: physical size and error correction level.

The 10:1 rule for print size

The rule of thumb from Denso Wave (who invented QR codes): the code should be at least 1/10th the distance from which it will be scanned.

  • Business card (scanned at ~20 cm): 2 cm × 2 cm minimum.
  • Poster or flyer (scanned at ~50 cm): 5 cm × 5 cm.
  • Storefront window (scanned from 2 m): 20 cm × 20 cm.
  • Billboard (scanned from 15 m): 1.5 m × 1.5 m.

Smaller than that and phone cameras start to fail — especially in low light, at odd angles, or with older phones. Add 25% for outdoor or high-motion contexts (menus in a moving vehicle, event signage passed on foot).

Error correction level — the L, M, Q, H trade-off

QR codes have built-in Reed-Solomon error correction. If part of the code is dirty, torn, or covered by a logo, the code can still be decoded. There are four levels:

LevelRecovers up toBest for
L (Low)7%Clean digital display, small file size.
M (Medium)15%Print, general use — the default.
Q (Quartile)25%Slightly dirty environments, small logos.
H (High)30%Outdoors, packaging, codes with a centered logo overlay.

Higher error correction = more pixels = a denser, less scannable code at the same physical size. The rule: use M for digital, H when you overlay a logo, Q for physical labels.

Quiet zone — the invisible margin that must exist

Every QR code needs a border of empty space around it — the quiet zone. The spec requires at least 4 modules (one "module" = one square in the code) of empty space on all sides. Codes printed right up to the edge of a business card, or with a decorative frame touching the code, will silently fail on half of phones.

Contrast and inversion

  • Dark on light is safest. Black on white, or dark navy on cream.
  • Light on dark (inverted colors) works on most modern scanners but fails on older Android cameras and industrial scanners. Avoid unless the code is digital-only.
  • Contrast ratio should be at least 4:1. Pastel-on-pastel codes look nice and don't scan.

Logo overlays — how big can you go?

A centered logo obscures part of the code, and error correction has to make up for it. Rules of thumb:

  • With H-level correction, the logo can cover up to ~25% of the code area (roughly a square 30–35% of the code's side length).
  • Keep the logo opaque — semi-transparent overlays confuse binarization.
  • Test on 5+ phones (iOS + Android, old + new) before printing 10,000 stickers.

File format for print vs digital

  • Print: export as SVG. It scales infinitely and never introduces JPEG artifacts.
  • Web / email: PNG at ≥300 px is fine.
  • Never JPEG a QR code — the compression artifacts merge modules and break decoding.

Generate one now

Our QR Code Generator supports URL, text, email, phone, WiFi, and vCard payloads, custom colors, logo overlay, all four error-correction levels, and PNG + SVG export. Everything is generated in your browser — no upload, no tracking pixel.

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