QR Code Size and Print Guidelines: How Small Is Too Small?

The smallest QR code that scans reliably is about 2 cm (0.8 in) wide when held in the hand, and for anything scanned from further away you should divide the distance by ten: a code read from 1 m should be about 10 cm wide. Leave a blank border of four modules on every side, print dark on light, and test a proof on the real material before the full run.

The 10:1 rule and where it comes from

Phone cameras resolve a code well when its width is roughly one tenth of the distance to the phone. The rule is a rule of thumb rather than a law, but it matches what people find in practice, and it gives sensible numbers:

For a distance that is not in the table, the QR code size calculator works out a minimum width.

Adjust the number for what is inside the code

Every QR code is a grid of squares called modules. The more data inside, the more modules, and the smaller each one is at a given width. A code holding a short link might have around 25 by 25 modules. One holding a long web address, Wi-Fi details or a full contact card can have 40 to 60 or more per side. If the printed width stays the same, the denser code has smaller modules and needs more size or a better print to scan.

Practical consequences:

• Prefer short links. A dynamic QR code holds only a short link, so the pattern stays coarse and easy to read on small labels.
• Trim a vCard to the essentials before putting it in a small code.
• Avoid putting long text in a code that will be printed small.

Adjust the number for the surface

Rough, textured or flexible materials blur the edges of modules. Uncoated cardboard, fabric, curved bottles and embroidery all need a larger code than smooth paper. As a starting point, add a quarter to a half more width, then test.

Keep the quiet zone

The QR standard (ISO/IEC 18004) specifies a quiet zone of at least four modules of empty space around the pattern. It lets the scanner separate the code from the surrounding design. Many designs that fail in the real world crop it: a box edge, a photo or a line of text touches the code.

Color, contrast and logos

• Use dark modules on a light background. A contrast ratio similar to black on white is ideal; very light foregrounds fail quickly.
• Avoid inverted codes (light on dark). Many scanners cannot read them.
• Use the highest error correction level if you add a logo, and keep the logo to about a fifth of the code or less. Error correction restores roughly 7, 15, 25 or 30 percent of the data at levels L, M, Q and H, but every module a logo covers uses some of that margin. See QR Code Error Correction Levels for how to choose.

File formats

For professional printing, export a vector file such as SVG or PDF. Vectors stay sharp at any size. If you only have a PNG, export it large, at least 1000 pixels wide, and print at 300 dpi at the final size. Do not scale up a small PNG, because the edges blur.

Test before you print the run

1. Print one copy at the real size on the real material.
2. Scan it with an iPhone and an Android phone from the real distance.
3. Scan it again under the real lighting.
4. Only then send the full order.

If the proof does not scan, work through the ten common causes.

FAQ

What is the smallest QR code that still scans?

On clean, flat, high-contrast print, about 2 cm (0.8 in) wide is a practical floor for a code held in the hand. Anything smaller needs a very simple pattern and excellent print quality, and gets unreliable quickly.

Is a bigger QR code always better?

Larger codes are easier to read from far away, but past the size you need there is no benefit. The code also has to fit the layout and keep its border.

Do I measure the code with or without the white border?

Measure the dark pattern only, then add the blank border of at least four modules on each side.