How to check if a QR code will scan
- Get an image of the codeUse the exact file you will print (PNG, JPG or SVG export). A screenshot of a PDF proof or a photo of a printed sample also works.
- Upload or drop it aboveYou can also paste an image from the clipboard.
- Read the score and the checksEach check shows how many points it earned and why.
- Apply the fixes and test againRegenerate the code in our QR code generator with the suggested changes, then upload the new version.
What the score means
The checker reads your image the way a phone would, then measures the properties that most often cause scanning failures. Each check carries a share of the 100 points:
| Check | Points | What we measure |
|---|---|---|
| Decodes | 40 | Whether the code can be read at all, and whether it needed image clean-up to read it |
| Contrast | 20 | The luminance contrast between the dark and light modules (dots) |
| Quiet zone | 15 | How many module-widths of empty border surround the code (4 is the standard) |
| Density | 15 | The QR version: how many modules the code has, which decides how large you must print it |
| Logo / covered area | 10 | An estimate of how much of the data area is hidden by a logo or graphics |
| Inverted colors | −15 | A penalty when the code uses light dots on a dark background |
A score of 85 or more means the code should scan reliably on almost every phone. Between 60 and 85 it will usually work, but some older phones or poor lighting may cause trouble. Below 60, fix the code before you print it.
The most common problems, and how to fix them
Low contrast. Pastel dots, gray on gray, or a brand color that is too light. Scanners convert the image to black and white, so the dots have to be clearly darker than the background. Aim for a contrast ratio of at least 4.5:1.
No quiet zone. Designers often crop the white border or place the code right against other graphics. The scanner uses that empty margin to find where the code starts. Keep at least four module-widths clear on all sides.
Logo too big. A logo hides data. Error correction can make up for it, but only up to a limit: about 30% at level H. Our estimate flags logos that cover too much of the code.
Too much data. Long links create dense codes with tiny modules. Shorten the link, remove tracking parameters, or print the code larger. The size calculator tells you how large.
Inverted colors. White dots on black can look stylish, and newer iPhones and many Android phones read them, but plenty of scanner apps and older devices don't. If the code is for the general public, use dark on light.
Limits of an automated check
This tool tests the digital file. Printing adds its own risks: glossy paper reflects light, curved surfaces such as bottles distort the code, and ink can spread on cheap paper and make modules merge. Always scan a physical proof with at least two phones before a large print run. For links, the QR safety scanner checks whether the destination looks trustworthy.
Frequently asked questions
Is my QR code uploaded anywhere?
No. The image is opened and analyzed by JavaScript in your browser. It never leaves your device.
Why is my score low even though my phone scans the code?
Modern phones are very forgiving. The score tells you how much safety margin the code has for older phones, bad lighting, small prints and worn surfaces.
What is a good scannability score?
85 or above is excellent. 60 to 85 is acceptable but improvable. Below 60, many people will fail to scan it.
Can it check a QR code on a photo of a poster?
Yes, as long as the code is reasonably sharp and fills a decent part of the photo. Tilted photos work too, but the quiet-zone measurement is less precise.
What is a module?
A module is one square cell of the QR grid, the smallest dot. A version-1 code has 21 × 21 modules and a version-10 code has 57 × 57.
How is the logo coverage estimated?
We sample every module and count the ones whose color matches neither the dark nor the light color of the code, plus any large blank area in the middle. It is an estimate, so treat it as a guide.
Does the checker tell me if a link is safe?
It shows the decoded content. To analyze a link for scam patterns, use the QR code safety scanner.
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Last updated October 27, 2026 by the PloraKit team. Found a problem? Tell us.
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