Why a logo works at all: error correction
Every QR code carries redundant data so it can still be read when part of it is damaged, dirty or covered. That is what makes a logo possible. There are four levels:
| Level | Damage it can repair | Largest sensible logo area |
|---|---|---|
| L — Low | 7% | Not recommended with a logo |
| M — Medium | 15% | Up to about 10% |
| Q — High | 25% | Up to about 15% |
| H — Highest | 30% | Up to about 22% |
Note that the percentages are not interchangeable: 30% error correction does not mean a logo can cover 30% of the code. The correction budget also has to absorb print imperfections, dirt, glare and a bad camera angle. Spending all of it on the logo leaves nothing for the real world.
The numbers we actually measured
We did not guess these limits. We generated codes at each logo size and ran them through a real QR decoder:
- Up to 22% — reads reliably with error correction H. This is the default here
- 25% — starts to fail on some readers
- 30% — many readers could not decode it at all
That is why the tool warns you above 24% instead of quietly letting you export something that fails on a poster. We would rather tell you now than have you find out after the print run.
Getting the logo itself right
- Simple shapes — a mark, a monogram or an icon. Fine detail disappears at code size anyway
- Solid background behind it — turn on the backing plate so the logo does not blend into the modules
- Clear the modules underneath — cleaner than overlaying, and the decoder treats it as one lost block instead of noise
- Square or round — a wide horizontal logo eats far more modules than its area suggests
- Transparent PNG or SVG — a white rectangle around your logo wastes error correction budget
And always: set error correction to H when a logo is present, then scan the result with two different phones before you commit it to print.
How to add a logo to a QR code
- Create the code firstEnter your content and check the code scans cleanly without a logo.
- Set error correction to HSettings tab → Highest. This is what buys you room for the logo.
- Upload the logoLogo tab → drag your file in. A transparent PNG or an SVG works best.
- Keep the size under 22%Watch the warning under the preview. Above 24% the tool will tell you the risk.
- Test on two phonesA logo changes the pattern. Never print without scanning the real thing first.
Frequently asked questions
Does a logo stop the code working?
Not if you stay within the error correction budget. Up to about 22% of the width with level H reads reliably in our tests. Beyond that, failures start.
What file formats can I upload?
PNG, JPG, SVG and WEBP. Transparent PNG or SVG gives the best result.
Is my logo uploaded to a server?
No. The file is read in your browser and drawn straight onto the code. It is never uploaded anywhere.
Is there a watermark on the download?
No. Downloads carry no watermark, signature or site name in any format.
Can I put the logo somewhere other than the centre?
The centre is the safest position because it is furthest from the three finder patterns in the corners, which must stay intact.