What types of data can I encode in a QR code?

This tool supports encoding plain text, URLs, email addresses (mailto: links), phone numbers (tel: links), WiFi network credentials (SSID, password, encryption type), and vCard contact information. Any text string up to the QR code capacity limit can be encoded.

QR Code Generator | QuickUtil.dev

How It Works

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100% Client-Side

QR codes are generated entirely in your browser using the HTML5 Canvas API. No data is ever sent to a server. Your content stays private and secure on your device.

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Customizable Design

Choose custom foreground and background colors, adjust the output size from 100px to 500px, and select the error correction level that fits your needs.

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Multiple Input Types

Generate QR codes for URLs, plain text, email addresses, phone numbers, WiFi network credentials, and vCard contact cards with pre-filled templates.

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Download as PNG

Download your generated QR code as a high-quality PNG image. Use it in print materials, presentations, websites, business cards, and more.

Understanding QR Codes

QR (Quick Response) codes are two-dimensional barcodes invented in 1994 by Denso Wave, a Toyota subsidiary. Unlike traditional one-dimensional barcodes that store data in a single row of bars, QR codes store data in a matrix of black and white modules arranged in a square grid. This allows them to encode significantly more information -- up to 7,089 numeric characters or 4,296 alphanumeric characters in a single code.

QR Code Structure

Every QR code contains several key structural elements:

Finder Patterns: Three large squares in the corners (top-left, top-right, bottom-left) that help scanners locate and orient the QR code.
Alignment Patterns: Smaller squares that help correct distortion, especially in larger QR codes (version 2+).
Timing Patterns: Alternating black and white modules between finder patterns that help determine module coordinates.
Format Information: Encodes the error correction level and mask pattern used.
Data and Error Correction: The actual encoded data plus Reed-Solomon error correction codewords.

Error Correction Levels

QR codes use Reed-Solomon error correction to remain readable even when partially damaged. Four levels are available:

Level L (Low): Approximately 7% of data can be restored. Best for clean environments where the code won't be damaged.
Level M (Medium): Approximately 15% recovery. A good default for most use cases.
Level Q (Quartile): Approximately 25% recovery. Good for codes that may get slightly dirty or damaged.
Level H (High): Approximately 30% recovery. Use when the code may be significantly obscured, or when adding a logo overlay.

Common Use Cases

Website Links: Encode URLs for easy sharing on print materials, posters, and business cards.
WiFi Sharing: Guests can scan a QR code to automatically connect to your WiFi network without typing the password.
Contact Cards: Encode vCard data so contacts can save your information by scanning the code.
Payments: QR codes are widely used in mobile payment systems around the world.
Authentication: Two-factor authentication apps use QR codes to exchange TOTP secrets.

Frequently Asked Questions

What is a QR code? ▼

A QR (Quick Response) code is a two-dimensional barcode that stores data in a matrix of black and white squares. Invented in 1994 by Denso Wave, QR codes can encode URLs, text, contact information, WiFi credentials, and more. They are designed to be scanned quickly by smartphone cameras and dedicated QR code readers, making them widely used for sharing information in both digital and physical contexts.

Is this QR code generator free? ▼

Yes, this QR code generator is completely free with no sign-up, no watermarks, and no usage limits. All QR code generation happens entirely in your browser using client-side JavaScript and the HTML5 Canvas API. No data is sent to any server. You can generate unlimited QR codes and download them as PNG images.

What is error correction in QR codes? ▼

Error correction allows a QR code to remain scannable even if part of it is damaged, dirty, or obscured. QR codes use Reed-Solomon error correction with four levels: L (7% recovery), M (15% recovery), Q (25% recovery), and H (30% recovery). Higher error correction means more data redundancy, which increases the QR code size but makes it more resilient. Level M is recommended for most use cases.

What types of data can I encode? ▼

This tool supports encoding plain text, URLs, email addresses (mailto: links), phone numbers (tel: links), WiFi network credentials (SSID, password, and encryption type), and vCard contact information. The tool uses numeric, alphanumeric, and byte encoding modes automatically based on your input. Any text string up to the QR code capacity limit can be encoded.

Can I customize the colors of my QR code? ▼

Yes, you can customize both the foreground (dark modules) and background colors using the color pickers. For best scanning reliability, maintain high contrast between the foreground and background. A dark foreground on a light background is strongly recommended. Some scanners may have difficulty reading QR codes with low contrast or unusual color combinations.

How do I create a WiFi QR code? ▼

Select "WiFi" from the Input Type dropdown. The tool will pre-fill a WiFi template in the format WIFI:S:NetworkName;T:WPA;P:password;;. Replace NetworkName with your WiFi SSID and password with your actual WiFi password. Change WPA to WEP or nopass as needed. When scanned by a smartphone, this QR code will automatically connect the device to your WiFi network without manually typing the password.

What is the maximum data capacity? ▼

The maximum data capacity depends on the QR code version (1-40) and error correction level. At Level L, a Version 40 QR code can store up to 7,089 numeric characters, 4,296 alphanumeric characters, or 2,953 bytes of binary data. Higher error correction levels reduce capacity. For typical use cases like URLs and short text, QR versions 1-10 are sufficient. The tool automatically selects the smallest version that fits your data.

Is my data secure? ▼

Yes, your data is completely secure. This QR code generator runs entirely in your browser using client-side JavaScript and the HTML5 Canvas API. No data is sent to any server, stored, or logged. The QR code is generated and rendered locally on your device. You can verify this by checking your browser's network tab -- no requests are made during generation.

QR Code Generator