QR Code Generator
Generate QR codes from any text or URL with customizable size and error correction level.
- Free
- No account
- Runs in your browser
- Nothing uploaded
Enter text or a URL and click Generate — the QR code is created in your browser and never sent anywhere.
Runs entirely in your browser — your input is never uploaded, logged, or stored.Privacy policy
What is QR Code Generator?
A QR code (Quick Response code) is a two-dimensional barcode that stores data in a grid of black and white squares. Unlike traditional barcodes that hold data in one direction, QR codes store information both horizontally and vertically — which means they can hold up to 7,089 numeric characters or 4,296 alphanumeric characters in a single symbol.
QR codes are defined by the ISO/IEC 18004 standard. Each QR code has four error correction levels that determine how much damage the code can withstand and still be readable: • L (Low): Recovers ~7% of data — smallest code, best for clean environments. • M (Medium): Recovers ~15% of data — good balance for most use cases. • Q (Quartile): Recovers ~25% of data — useful when codes might be partially obscured. • H (High): Recovers ~30% of data — largest code, best for logos overlaid on the center.
This tool generates QR codes entirely in your browser using client-side JavaScript. No data is sent to any server. You can verify this by checking your browser's network tab: there are no outbound requests when you generate a QR code.
The generated image is a PNG that you can download and use anywhere — websites, documents, presentations, or print materials. The QR code is scannable by any standard QR reader, including smartphone cameras.
QR code generation follows the ISO/IEC 18004 specification:
1. The input data is analyzed to determine the most efficient encoding mode: - Numeric mode (0-9): most efficient for numbers. - Alphanumeric mode (0-9, A-Z, space, $%*+-./:): efficient for uppercase text. - Byte mode (any UTF-8): default for mixed or lowercase text.
2. The data is encoded into a bit stream using the selected mode.
3. Error correction codewords are added using Reed-Solomon coding. The number of EC codewords depends on the error correction level (L=7%, M=15%, Q=25%, H=30%).
4. The bit stream is arranged into a matrix pattern with finder patterns (the three large squares in the corners), alignment patterns, timing patterns, and the encoded data modules.
5. A mask pattern is applied to balance the distribution of dark and light modules, improving scannability. The optimal mask is selected automatically.
6. Format and version information is added to complete the QR code.
Worked examples
- Generate a QR code for "https://allutil.com" at 256×256 pixels: produces a 25×25 module QR code (version 2) in Byte mode with error correction level L.
- Generate a QR code for "Hello, World!" with error correction level H: produces a 25×25 module QR code (version 2) — slightly larger than L level because H adds more error correction data.
- Generate a QR code for "1234567890": produces a 21×21 module QR code (version 1) using Numeric mode, the most efficient encoding for pure numbers.
- Generate a QR code for "QR Code Generator": produces a 21×21 module QR code (version 1) in Byte mode — fits in the smallest possible QR code.
How to use QR Code Generator
- Enter the text or URL you want to encode in the input field.
- Choose a size (128, 256, 512, or 1024 pixels) — 256 works well for most uses.
- Select an error correction level — L for smallest code, H if you want to overlay a logo.
- Click Generate to create the QR code, then Download to save it as a PNG file.
Common errors
- QR code looks blurry when printed — the image resolution is fixed by the pixel size you select. Use 512 or 1024 for print materials, 256 for screen display.
- QR code won't scan after resizing — some image editors introduce artifacts when resizing. Download the original PNG and use that directly instead of resizing.
- QR code is too large for the space — use error correction level L (lowest) to minimize the code size, or reduce the pixel dimensions.
- Camera says 'unable to decode' — the data might be too long for the selected error correction level. Try L level or shorten the URL using a shortener.
FAQ
How much data can a QR code hold?
Depends on the encoding mode and error correction level. At the maximum (version 40, level L): 7,089 numeric characters, 4,296 alphanumeric characters, or 2,953 bytes of binary data. In practice, keep QR codes short — under 100 characters for reliable scanning on all devices.
Can I add a logo or image to the center of the QR code?
Yes, but only if you use error correction level H (30% recovery). The logo can cover up to 30% of the code and it will still scan. Use level L or M and a logo will make the code unscannable.
What's the difference between PNG and SVG for QR codes?
PNG is a raster format — fixed pixel resolution, good for most uses. SVG is vector — scales infinitely without losing quality, ideal for print materials that need to be resized. This tool generates PNG; for SVG you'd need a different library.
Why are there three big squares in the corners?
Those are finder patterns. They help QR scanners locate and orient the code quickly, regardless of rotation angle. Every QR code has them — they're part of the ISO standard, not decorative.
Is this safe for sensitive data like passwords?
QR codes are not encrypted. Anyone who scans the code can read the data. For sensitive information, use QR codes to point to a secure URL that requires authentication, not to embed the secret directly.
Related tools
Prefer AllUtil on Google
One click adds AllUtil to your Google preferences. You'll see our tools highlighted with a Preferred badge in Search and AI answers.