QR code glossary · Encoding and capacity
QR code version
Also called: Symbol version
Definition
A QR code’s version is its size on a scale from 1 to 40: version 1 is 21 × 21 modules and each version adds 4 modules per side, up to 177 × 177 at version 40, so a version V code is 17 + 4V modules across.
How it works
The version is not a software release; it is the symbol size. The encoder normally picks the smallest version whose capacity fits the content at the chosen error correction level. More content or more error correction means a higher version. Codes of version 7 and above record their version in two blocks of version information; smaller ones are identified by their module count.
| Version | Modules | Bytes at L | Bytes at M | Bytes at H |
|---|---|---|---|---|
| 1 | 21 × 21 | 17 | 14 | 7 |
| 2 | 25 × 25 | 32 | 26 | 14 |
| 3 | 29 × 29 | 53 | 42 | 24 |
| 5 | 37 × 37 | 106 | 84 | 44 |
| 7 | 45 × 45 | 154 | 122 | 64 |
| 10 | 57 × 57 | 271 | 213 | 119 |
| 20 | 97 × 97 | 858 | 666 | 382 |
| 40 | 177 × 177 | 2,953 | 2,331 | 1,273 |
The versions belong to QR code Model 2, the form in use today. The original Model 1 went up to version 14 and is obsolete.
Why it matters
A higher version packs more modules into the same printed width, so each module is smaller and the code must be printed larger, or scanned from closer, to read reliably. The standard allows version 40, but codes that big are impractical for phones at everyday print sizes. Everyday codes are small versions: a short link fits version 3 at level M.
You rarely choose a version directly. You influence it through what you encode and the error correction level. Shorter content, such as a short URL instead of a long address with tracking tags, is the most effective way to keep the version low.
Example
The same destination two ways, both at level M: the 90-character link with campaign tags needs version 6, while a 28-character short link needs version 3.
Related terms
- ModuleA module is a single square cell of a QR code, either dark or light, and the basic unit of the symbol: each one is a bit of data or part of a fixed pattern, and the printed width of one module decides how far away the code can be read.
- Data capacityData capacity is the most content a QR code can hold, which depends on its version, error correction level and encoding mode; the largest code, version 40 at level L, holds 7,089 numeric digits, 4,296 alphanumeric characters, 2,953 bytes or 1,817 kanji characters.
- Error correction levelAn error correction level is the setting, L, M, Q or H, that decides how much redundant data a QR code carries; the four levels let a scanner restore roughly 7%, 15%, 25% and 30% of the code’s codewords when they are damaged, dirty or covered.
- Encoding modesEncoding modes are the ways a QR code packs characters into bits: numeric mode for digits, alphanumeric mode for a 45-character set of capital letters, digits and a few symbols, byte mode for any data such as UTF-8 text, and kanji mode for Japanese Shift JIS characters.
- Alignment patternAn alignment pattern is a small 5 × 5 module square, a dark ring around a light ring around a single dark module, placed at regular intervals inside QR codes of version 2 and above so a scanner can correct for tilt, perspective and curved surfaces.
- Format informationFormat information is a 15-bit field printed twice in every QR code, beside the finder patterns, that tells the scanner which error correction level and which mask pattern the code uses, so it can be read before any of the data.
Learn more
- QR code size guide: How density changes the print size you need.
- Dynamic vs static QR codes: Why short links make simpler codes.
Sources
Last updated . Written by the CirculateQR team; technical facts follow the sources listed above. Example codes and sizes are computed with the open-source qrcode encoder that CirculateQR uses. Spotted something wrong? Email support@circulateqr.com. QR Code is a registered trademark of DENSO WAVE INCORPORATED.
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