How big can a QR code logo be before it stops scanning?
Smaller than you think. Keep a centered logo's width under about a third of the code, and always use error correction level H.
The "you can cover 20 to 30%" figure you see on almost every other page is a misread of how QR codes actually work. Follow it and you get a logo that looks fine on your screen and fails on the printed piece.
Why "30%" is the wrong number
Search this question and you'll find the same claim everywhere: "error correction level H lets a logo cover up to 30% of the code." That number comes from a real fact, repeated wrong.
Level H can rebuild about 30% of a QR code's data if that data gets damaged. People hear "30%" and assume a logo can cover 30% of the code. It can't, for two reasons.
First, error correction only protects the data area. It does nothing for the three big squares in the corners, the dotted timing lines that run between them, or the smaller alignment square. Those are the patterns a scanner uses to find and lock onto the code in the first place. A logo that grows into any of them kills the scan outright, no matter which level you picked. On a small code, a centered logo reaches them sooner than you would guess.
Second, that 30% assumes the damage is spread out, like scratches and coffee stains scattered across the whole code. A logo is the opposite. It wipes out one solid block in the middle. Error correction handles scattered damage far better than one concentrated hole, so a centered logo eats into your margin much faster than a flat percentage suggests. The safe coverage lands well below the 30% people quote.
Width versus area, the trap nobody mentions
There is a second reason logos end up too big, and it is pure geometry. People size a logo by its width. Scanning depends on its area. And area grows with the square of width.
A logo whose width spans 40% of the code covers only about 16% of its area. So "my logo takes up 40%" and "keep it small" can both be true at once. They are measuring different things. When a logo looks modest to your eye, it is usually covering more of the code than you think.
The number your generator shows you isn't the coverage
One more thing to distrust: the "logo size" value a generator shows you, like 0.4 or 40%, usually isn't the share of the code your logo covers. Depending on the tool, that slider is scaled to other settings, so a "40%" can put much less (or more) than 40% of the code under your logo.
Don't read the slider as coverage. Judge the logo by eye against the code, keep it clearly small, and test the finished file.
This is why QR Codes Made Easy keeps the logo small and forces level H for you, on the safe side of the line, because a code you print is a code you can't take back.
How to add a logo without breaking the scan
- Use error correction level H. It is the highest of the four levels and the only one with real margin to spare for a logo. If your generator lets you choose, choose H. Some switch to it the moment you add an image.
- Keep the logo small. Width under about a third of the code. When in doubt, smaller. A logo that stops the code from scanning is not doing your brand any favors.
- Center it and give it a white pad. A logo sitting on a small white background keeps its edges from blurring into the code's dots, and centering keeps it clear of the corner patterns.
- Keep strong contrast and the quiet zone. Dark code on a light background, and leave the empty margin around the code (about four dots wide) alone. Contrast and that border matter as much as logo size.
- Test before you print. Scan the finished file with two different phones, one iPhone and one Android, from the distance people will actually use. It is the last step on the pre-print checklist, and the one that saves the reprint.
That covers the scan. Where to place a code, how big to make it on each surface, and the contrast rules that survive real ink are what goes in the Brand Field Guide to QR Codes.
FAQ
How much of a QR code can a logo cover?
Less than the "30%" you will read elsewhere. Because error correction protects only the data area, and handles one concentrated block poorly, the safe covered share is well under that. A good working rule is a logo width under about a third of the code, at error correction level H. When it matters, keep it smaller and test.
What error correction level should I use for a QR code with a logo?
Level H, every time. It is the highest of the four levels (L, M, Q, H) and the only one with enough spare capacity to survive a logo covering part of the code. The lower levels leave almost no room once an image sits on top.
What happens if the logo is too big?
The code stops scanning. It usually doesn't get "slower," it just fails, because the logo either erases more data than error correction can rebuild or grows into the corner and timing patterns a scanner needs to lock onto the code. The jump from "works" to "dead" is small, which is why testing matters.
Does putting a logo in the middle affect scanning?
Yes, but the middle is the safest place for it. A centered logo stays away from the three corner squares and the alignment square, the patterns error correction can't protect. Keep it centered and keep it small.
Can I put any logo on a QR code?
Mostly, if you keep it small and high contrast. A simple, solid logo on a white pad works best. Thin lines, low contrast, or a logo that fades into the code's dots will hurt scanning more than a bold, compact mark of the same size.
How do I test that my QR code still scans?
Open the exported file at full size and scan it with two phones, one iPhone and one Android, from the distance your audience will use. Test the actual file you're sending to print, not the preview. If both phones read it instantly, you're good.
Make one that scans
QR Codes Made Easy keeps the logo at a safe size and uses level H for you. Free, no account, and the code never expires.
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