QR code glossary · QR code basics
Micro QR code
Also called: Micro QR
Definition
A Micro QR code is a smaller variant of the QR code, defined in the same standard (ISO/IEC 18004), that uses a single finder pattern and a 2-module quiet zone to fit up to 35 digits in a symbol of 11 × 11 to 17 × 17 modules.
How it works
A regular QR code spends a lot of space on its three finder patterns and 4-module quiet zone. Micro QR keeps one finder pattern in the top-left corner, runs its timing patterns along the top and left edges, has no alignment patterns and needs only a 2-module quiet zone. It also uses four mask patterns instead of eight.
| Version | Modules | Error correction | Max digits | Max bytes |
|---|---|---|---|---|
| M1 | 11 × 11 | Error detection only | 5 | – |
| M2 | 13 × 13 | L, M | 10 | – |
| M3 | 15 × 15 | L, M | 23 | 9 |
| M4 | 17 × 17 | L, M, Q | 35 | 15 |
There is no level H. M4 at level L holds 35 digits, 21 alphanumeric characters, 15 bytes or 9 kanji, against 7,089 digits for the largest regular QR code.
Why it matters
Micro QR suits marking where space is tiny and the content is a short serial number, such as electronic components and small parts. It is a poor fit for consumer use: 15 bytes is too little for almost any web address, and support in phone camera apps is limited and inconsistent, so Micro QR is mostly read by dedicated industrial scanners. If you consider it, test with the exact devices that will read it.
For long, narrow spaces there is also the rectangular Micro QR code (rMQR), standardized separately as ISO/IEC 23941 in 2022. For anything people will scan with a phone, a regular QR code holding a short link is the safer choice; at version 1 it is still only 21 modules across.
In CirculateQR
CirculateQR generates regular QR codes only, not Micro QR or rMQR.
Related terms
- QR codeA QR code (Quick Response code) is a square two-dimensional barcode, standardized as ISO/IEC 18004, that stores data such as a web address, contact card or WiFi login in a grid of dark and light squares that a phone camera can read in any orientation.
- Quiet zoneThe quiet zone is the blank margin that must surround a QR code on all four sides so a scanner can tell where the code begins; ISO/IEC 18004 requires it to be at least 4 modules wide for a regular QR code and 2 modules for a Micro QR code.
- Finder patternA finder pattern is one of the three large concentric squares in the top-left, top-right and bottom-left corners of a QR code, which a scanner uses to detect the code, measure its size and angle, and work out which way up it is.
- 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.
- 2D barcodeA 2D barcode is a barcode that stores data across both the width and the height of its pattern, unlike a 1D (linear) barcode such as a UPC, which stores a short number in the widths of its bars; QR codes, Data Matrix, Aztec and PDF417 are all 2D barcodes.
Learn more
- QR code size guide: How small a regular QR code can be printed.
- QR codes on packaging: Print specs for codes on products.
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.
← Browse the full glossary