QR Logo Safe-Area Checker - Free Online Tool
Check how much of your QR code a centre logo covers and whether the scan is still likely to succeed.
Drop your QR code image here
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How to check if your QR code logo is too large
Upload your QR code image and enter the logo width and height as a percentage of the QR code size. The tool detects the QR boundaries, calculates the area coverage, and overlays a coloured highlight on the preview showing exactly how much of the code the logo occupies. Green means the logo is within the safe zone. Amber means you need to use a higher error correction level. Red means the logo is too large to scan reliably regardless of error correction level.
If you do not know the exact logo percentage, measure the logo and QR dimensions in your design tool in the same unit, divide, and multiply by 100. For example, a 60 px logo on a 300 px QR code is 20%.
How QR error correction enables logos
Every QR code stores not just the encoded data but also a set of error correction codewords calculated using the Reed-Solomon algorithm. These codewords allow the decoder to reconstruct missing or corrupted modules up to a defined limit. There are four error correction levels: L (7%), M (15%), Q (25%), and H (30%). The percentage is the maximum proportion of the code data area that can be destroyed or obscured and still be fully reconstructed.
Placing a logo over the centre of a QR code destroys the modules underneath. As long as the logo stays within the headroom of the selected error correction level, the decoder recovers those modules from the remaining data and the scan succeeds. The checker tells you whether your logo size and the error correction level are matched correctly.
Error correction levels at a glance
| Level | Max coverage | Typical logo size |
|---|---|---|
| L - Low | 7% | Very small icon (~8% width) |
| M - Medium | 15% | Small logo (~12% width) |
| Q - Quartile | 25% | Medium logo (~16% width) |
| H - High | 30% | Standard logo (~17% width) |
Best practices for QR codes with logos
- Always generate the QR code with H error correction when adding a logo
- Keep the logo within 20% of the QR width to stay comfortably inside the 30% area limit
- Centre the logo exactly - off-centre placement may overlap finder patterns in the corners
- Add a white or solid-colour background behind the logo to fully mask the underlying modules
- Test the finished QR code on multiple devices and in varied lighting before printing
- Generate the QR at a high pixel resolution before adding the logo to preserve module clarity
Frequently asked questions
How much of a QR code can a logo cover before it fails to scan?
The maximum safe coverage depends on the error correction level used when the QR code was generated. At the highest level, H (High), a logo can cover up to approximately 30% of the QR data area and still scan correctly. At lower levels the headroom is smaller: Q allows up to 25%, M allows up to 15%, and L (Low) allows only 7%. Exceeding these thresholds means there is not enough redundant data for the decoder to reconstruct damaged or obscured modules.
What is error correction and why does it matter for logos?
QR codes use Reed-Solomon error correction to encode redundant data. This redundancy allows the decoder to recover information even when part of the code is obscured, damaged, or unreadable. When you place a logo over the centre of a QR code, it destroys the modules underneath. As long as the logo covers less of the code than the error correction headroom allows, the decoder can reconstruct the missing data from the remaining modules. If the logo is too large, there is not enough redundancy left and the code cannot be recovered.
Which error correction level should I use for a QR code with a logo?
Use H (High) whenever you plan to add a logo to a QR code. H provides 30% error correction headroom, which is enough for a logo that is roughly 20–25% of the QR width on each axis. Using Q or M limits how large the logo can be before scan reliability is affected. Avoid using L (Low) for any QR code that will have an overlaid logo.
How do I enter the logo size in the tool?
Upload your QR code image and enter the logo width and height as a percentage of the QR code dimensions. For example, if your QR code is 400 × 400 pixels and your logo is 80 × 80 pixels, enter 20 for both width and height (80 is 20% of 400). The tool calculates the area coverage and shows a coloured overlay on the QR preview so you can see exactly how much of the code the logo occupies.
My QR code still scans with a large logo - is the tool wrong?
Not necessarily. The 30% threshold is a conservative maximum based on the error correction specification. Some decoders, particularly flagship smartphones with advanced image processing, may successfully decode a code where the logo covers somewhat more than 30%. However, relying on this is risky: the code may fail on lower-end devices, at angle, in dim lighting, or after printing. The tool flags coverage above 30% as a failure to identify codes that will not be universally reliable.
Does the logo position matter, or just the size?
Position matters significantly. QR codes have three fixed finder patterns in the corners and a timing pattern along the top and left edges. If the logo overlaps a finder pattern or the timing strip, the scanner may be unable to locate or orient the code regardless of error correction level. Logos should always be placed in the centre of the QR code, away from the corners. The tool assumes a centred logo, which is the correct placement for all branded QR codes.
Does adding a logo change the QR code I need to regenerate?
No - the logo is placed over an existing generated QR code; it does not change the encoded data. However, you must generate the QR code at the appropriate error correction level before adding the logo. If you generate at L and then add a logo, the underlying code may not have enough redundancy. Always choose your error correction level first, generate the QR, then overlay the logo.
Can I use a transparent or semi-transparent logo?
Partially. If a logo is fully transparent, it does not obscure any modules and has no coverage penalty. If it has partial transparency, the exposed modules underneath may still be detectable by the scanner depending on contrast and how much of the module is visible. The safest approach is to use a solid (opaque) logo with a white or background-coloured backing, sized within the error correction headroom.
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