What is a QR Code?

A QR code (Quick Response code) is a two-dimensional barcode that can store up to several kilobytes of text, URLs, contact information, Wi-Fi credentials, and more. Originally invented by Denso Wave in 1994 for automotive manufacturing, QR codes became ubiquitous in everyday life — from restaurant menus to boarding passes to payment systems.

QR codes are readable by any modern smartphone camera without a dedicated app. A square grid of black and white modules encodes data using error-correcting codes, which means a QR code can still be scanned even if part of it is damaged or obscured.

Common Use Cases

Links and URLs — You can create a QR code with the website address link, so users don’t have to type it in.
Wi-Fi credentials — Scan to connect: WIFI:S:MyNetwork;T:WPA;P:password;;
Contact cards (vCard) — Share phone numbers, emails, and addresses
Payment and invoices — Many payment apps (WeChat Pay, PIX, UPI) use QR
Product packaging — Link to product manuals, authenticity certificates
Event tickets — Digital tickets scanned at entry
Marketing materials — Print on posters, business cards, or product packaging

Error Correction Levels Explained

QR codes have four error correction levels that control how much of the code can be damaged while remaining scannable:

Level	Recovery Capacity	Best For
L	~7%	Clean digital displays; maximum data density
M	~15%	General use (default recommendation)
Q	~25%	Industrial environments with some damage risk
H	~30%	Logos overlaid on the QR code; harsh environments

Higher correction levels produce larger, denser codes. Use M for most purposes. Use H if you plan to place a logo in the center of the QR code.

How to Use This Tool

Type or paste your text, URL, or any data in the input box.
Adjust the size with the slider — 256px is good for screen display; 512px for print.
Choose colors — the foreground (dark modules) and background colors. Keep sufficient contrast for reliable scanning.
Select error correction level — M works for most cases.
Download as PNG for use in documents, presentations, or print.

Frequently Asked Questions

What is the maximum amount of data a QR code can store?

The QR code standard supports up to 7,089 numeric characters, 4,296 alphanumeric characters, or 2,953 bytes of binary data. In practice, shorter content produces smaller, easier-to-scan codes.

Can I use custom colors?

Yes — any foreground and background color combination works. However, always maintain high contrast between the two colors. Light foreground on dark background (inverted) also works, but some older scanners may have difficulty. Avoid low-contrast combinations like light gray on white.

Is it possible to add a logo to the QR code?

This tool generates plain QR codes. To add a logo, choose H (highest error correction), download the PNG, and then overlay your logo using an image editor. The H level can recover ~30% of damaged modules, which is enough to accommodate a central logo of up to ~20% of the code area.

What resolution should I use for printing?

For print, use at least 300 DPI. As a guide: to print at 2×2 cm at 300 DPI you need about 236px. For a business card (5×5 cm) use 512px or higher. When in doubt, use the highest size this tool offers and let your design software scale it down with “preserve quality” enabled.

Why does my QR code not scan?

Common reasons:

Too little contrast between foreground and background
Too much data in a small code — try a shorter URL (use a URL shortener) or increase size
Camera too close or too far — QR codes have a minimum print/display size
Low error correction combined with a dirty or damaged surface — try level Q or H