How to Generate QR Codes That Actually Work — Complete Guide

I once printed 200 flyers for an event with a QR code that linked to the registration page. At the venue, people kept telling me the code would not scan. I tested it myself — nothing. The problem? I had placed a large logo in the center of the QR code using Low error correction. The logo covered too much of the data, and the code became unreadable. I had to reprint everything. Here is what I learned about creating QR codes that scan the first time, every time.

How QR Codes Actually Work

A QR code is a two-dimensional barcode that stores data in a grid of black and white squares. When you point your phone camera at it, the phone decodes the pattern back into the original information — a URL, text, phone number, or WiFi credentials.

QR codes have built-in error correction. This means the code can still be read even if part of it is damaged, dirty, or covered. Error correction comes in four levels, and choosing the right one is the single most important decision you make when creating a QR code.

Error Correction Levels — This Is What Matters

If you are putting a logo in the center of your QR code, you must use H (High) error correction. The logo covers part of the data, and the error correction makes up for it. Using L or M with a logo is why most branded QR codes fail to scan. Our QR Generator defaults to High error correction when you add a logo for exactly this reason.

QR Code Size and Scanning Distance

The physical size of your QR code determines how far away it can be scanned. The general rule: the scanning distance should be roughly 10 times the width of the QR code. A 2 cm wide QR code scans reliably from about 20 cm away. A 10 cm wide QR code on a poster can be scanned from about 1 meter away.

For business cards, 2-3 cm works. For flyers and brochures, 3-5 cm. For posters and signage, 5-10 cm or larger. Do not go below 2 cm — smaller than that and many phone cameras struggle to focus.

Color and Contrast Rules

The QR code needs a dark foreground on a light background. Black on white is the safest and most reliable. You can use colors — dark blue on white, dark green on light yellow — but the contrast must be high. The foreground must be significantly darker than the background. Avoid light colors for the code itself.

Never invert the colors. A white QR code on a black background looks stylish but many barcode readers and older phones cannot read inverted QR codes. If you want a dark-themed design, put a white border around the QR code area and keep the code itself dark on light.

What You Can Store in a QR Code

• Website URLs: The most common use — link to your site, a product page, or a registration form
• Plain text: Display a message when scanned — useful for instructions or contact info
• WiFi credentials: Let guests connect to your WiFi by scanning the code
• Phone numbers: Scanning opens the phone app with the number pre-filled
• Email addresses: Scanning opens the email app with the address pre-filled
• vCards: Share contact information that can be saved directly to the phone's address book

The more data you store, the denser the QR code becomes. Dense QR codes need to be printed larger to scan reliably. For most uses — URLs, short text, WiFi — the size stays manageable.

How to Generate a QR Code

Our QR Generator creates codes in seconds:

1. Open the generator and choose what type of content you want to encode (URL, text, WiFi, etc.)
2. Enter your data — the URL, the message, or the WiFi password
3. Choose error correction level (H is recommended if you plan to add a logo)
4. Optionally upload a logo image to place in the center
5. Click Generate and download your QR code as a PNG image

The QR code is generated entirely in your browser. No data is sent anywhere. If you need to create multiple QR codes for different purposes, you can generate them one after another with no limits.

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