Testing & verification

Test your QR code
before printing

Decode and verify any QR code in seconds. Upload an image file to confirm the scanned content is correct — catch errors before a print run costs you money.

Free · No upload to server · Works in browser

2s

to decode any QR image

100%

browser-based, no upload

Free

no account required

PNG/SVG

file formats supported

Pre-print checklist

6 things to check before printing

Run through this checklist every time you create a new QR code to avoid costly reprints.

Decoded content is correct

Verify the URL or text decoded matches your intended destination exactly — including https:// and any UTM parameters.

Correct QR code size

Minimum 2 cm × 2 cm for handheld scanning. Scale up proportionally for larger scanning distances on signage.

Sufficient contrast

Dark modules on light background. Avoid placing QR codes on busy images or low-contrast surfaces.

Quiet zone intact

A clear white border (at least 4 modules wide) surrounds the QR code — never crop this margin.

Scans in low light

Test in dimmer conditions similar to where the QR will be displayed — restaurants, events, or retail floors.

Destination URL is live

Open the decoded URL in a browser to confirm the page loads. A broken link is the most common QR failure.

How it works

Test a QR code in 4 steps

1

Export your QR code

Download your QR code as PNG or SVG from QR Maker or any other generator.

2

Upload to the tester

Open QR Maker's scan tester and upload the image file. Decoding runs entirely in your browser.

3

Verify decoded content

Confirm the URL or text shown matches exactly what you intended. Look for typos and missing characters.

4

Physical scan test

Print at intended size and scan with a phone from the expected distance. Test in low-light too.

Troubleshooting

Why QR codes fail to scan

These are the four most common reasons a QR code doesn't work — and how to fix each one.

URL changed after printing

Static QR codes encode the URL permanently. Use a dynamic QR code so you can update the destination without reprinting.

Too small to scan

Business cards and flyers often have QR codes printed below the 2 cm minimum. Always confirm the final print size.

Low contrast or dark background

Inverted QR codes (light on dark) scan inconsistently on older devices. Stick to dark-on-light whenever possible.

Overly complex data

Long URLs pack more data into the QR, creating denser patterns. Use a URL shortener or dynamic QR code to reduce complexity.

FAQ

QR code testing questions

How do I test a QR code before printing?
Upload the QR code image to QR Maker's free tester tool. It decodes the QR code in your browser instantly, showing you exactly what content or URL it contains — without needing a phone.
What causes a QR code to fail to scan?
The most common causes are: too low contrast between QR and background, too small a size for the scanning distance, excessive customization that reduces error correction, or a URL that was changed after the QR code was created (for static QR codes).
Can I test a QR code without a phone?
Yes. QR Maker's browser-based tester decodes QR codes from image files using JavaScript — no phone camera required. Upload a PNG or SVG and see the decoded content immediately.
Should I test my QR code at print size?
Yes — always test at the final intended print size. A QR code that looks fine on screen may fail at 2 cm square on a business card. Print a test copy and scan it from the expected scan distance.
What is the minimum size for a printable QR code?
The minimum recommended size is 2 cm × 2 cm (about 0.8 inches) for a QR code scanned from roughly 20–30 cm away. For outdoor signage or posters, scale proportionally with scanning distance.