Why Logos Reduce Scan Reliability

A QR code isn't just a random collection of black and white squares.

Every tiny square (called a module) stores part of the encoded information. When you place a logo in the center, you're literally covering some of that data.

Fortunately, QR codes include something called error correction. This allows scanners to recover missing or damaged parts of the code.

Many QR code generators rely on this feature to make logo QR codes possible.

The catch is simple:

Error correction has limits.

The larger the logo becomes, the fewer mistakes the scanner can recover from.

Error Correction Isn't Magic

QR codes use a technology called Reed-'omon Error Correction, and it can use this algorithm to recover from missing data, but only up to a certain point.

There are four error correction levels:

• L – Recovers about 7% of damaged data
• M – Around 15%
• Q – Around 25%
• H – Up to 30%

Most QR codes can still be scan at Level H, the highest available, which mean 1/3 of the QR code is missing.

While that sounds generous, remember that the logo isn't the only thing competing for this margin.

Real-world conditions also damage QR codes:

• Dirt
• Scratches
• Low-quality printing
• Poor lighting
• Camera blur
• Wrinkles on paper
• Reflections from glossy surfaces

If your logo already consumes much of the available error correction, these additional imperfections can easily push the QR code beyond what scanners can recover.

Printing Makes the Problem Worse

A QR code displayed on a screen is usually sharp and high contrast.

Printed QR codes are a different story.

Printing introduces small imperfections that become more noticeable over time:

• Ink can spread slightly into neighboring modules.
• Paper texture reduces edge sharpness.
• Low-resolution printers blur fine details.
• Folding or creasing damages parts of the code.
• Sunlight and moisture can fade the print.

If you've already removed a large portion of the QR code by placing a logo in the middle, these printing issues leave even less room for successful scanning.

A QR code that scans perfectly on your computer monitor may become unreliable once it's printed.

Bigger Logos Create Bigger Risks

One common mistake is assuming:

"If a small logo works, a larger logo must look even better."

Unfortunately, that's not how QR codes work.

As the logo grows:

• More data is covered.
• The remaining modules become smaller.
• Scanners have less information available.
• Scan speed often decreases.
• Older phones may struggle to recognize the code.

Eventually, some devices simply won't scan the QR code at all.

Small QR Codes Leave Even Less Room

Logo QR codes become especially problematic when the overall QR code is small.

Imagine printing a QR code on:

• A business card
• A product label
• A sticker
• A keychain
• Product packaging

These QR codes already have tiny modules.

Adding a logo removes valuable scanning information while also shrinking the surrounding modules even further.

This combination can make scanning frustrating, especially from a distance.

More Data Means Less Flexibility

The amount of information stored inside a QR code also matters.

A QR code containing only a short URL is relatively simple.

A QR code containing:

• Long URLs
• Contact information
• Wi-Fi credentials
• Calendar events
• Large blocks of text

requires many more modules.

That leaves less unused space for a logo.

This is one reason why many professional QR campaigns use short URLs rather than encoding long pieces of information directly.

When Is a Logo Worth Using?

A logo can still make sense in certain situations.

For example:

• Brand marketing campaigns
• Product packaging
• Event signage
• Trade show displays
• Restaurant menus
• Company brochures

In these cases, brand recognition may outweigh the small reduction in scan reliability.

The key is moderation.

A small logo with generous white space around it is usually much safer than a large logo covering a significant portion of the QR code.

When You Should Skip the Logo

For many everyday uses, reliability matters far more than appearance.

Consider leaving the QR code plain if it's used for:

• Shipping labels
• Inventory tracking
• Equipment identification
• Industrial environments
• Outdoor signs
• Emergency information
• Tickets and access control
• Small printed materials

In these situations, every successful scan is more important than branding.

Tips for Using a Logo Safely

If you decide to include a logo, follow these best practices:

• Keep the logo as small as possible.
• Your logo should not cover more than 30% of your QR code.
• Don't cover the corner finder patterns.
• Print a test copy before mass production.
• Test with multiple phones, not just your own.
• Avoid using logos on very small QR codes.

Testing under real-world conditions is the best way to ensure your QR code remains reliable.

The Bottom Line

A logo can make a QR code look more attractive, but it always comes with a trade-off.

The more of the QR code you cover, the less room remains for handling printing imperfections, poor lighting, scratches, and camera limitations.

For digital use, a carefully sized logo is often acceptable.

For printed materials—especially small prints—the safest choice is usually a clean QR code without a logo.

If your goal is the highest possible scan success, simplicity always wins.