Level M recovers ~15% of damage.
(Documentation in English)
QR Code Generator
What it does
Encodes any text or URL into a QR code using a complete, from-scratch implementation of the ISO/IEC 18004 standard: all three data modes (numeric, alphanumeric, byte — picked automatically for the tightest fit), versions 1-40 (21×21 up to 177×177 modules), all four error-correction levels, Reed-Solomon error correction over GF(256), and automatic mask selection across all eight ISO mask patterns. Output is a crisp SVG (any scale, colors, quiet-zone size) or a PNG rendered at the chosen module size.
The encoder is verified against a published reference matrix, and everything runs locally — your text never leaves the page.
How to use
- Type or paste text into the box.
- Pick an error-correction level: L is smallest, H survives the most damage.
- Adjust module size, quiet zone and colors.
- Download the PNG, or copy the SVG markup to scale losslessly.
The page URL carries your full setup (text, level, colors, sizes) — Copy share link reopens it exactly.
Examples
https://dev.cosmolabs.org/ at level M encodes as version 2, byte mode.
HELLO WORLD at level Q encodes as version 1 in alphanumeric mode — 11
characters fit because alphanumeric packs two characters per 11 bits.
Long content grows the version automatically: up to 2,953 bytes at level L.
Good to know
- Higher error correction costs capacity: the same text grows a bigger symbol as you move from L to H.
- The quiet zone (light margin) is part of the spec — keep at least 4 modules for reliable scanning.
- Dark-on-light contrast matters more than colors: keep the foreground clearly darker than the background.
- SVG output scales infinitely; PNG rasterizes at the chosen module size.