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QR code

A QR code (Quick Response Code) is a two-dimensional matrix barcode that represents data in a pattern of dark and light modules. Developed by DENSO WAVE in Japan for rapid, high-capacity identification in manufacturing, it can be read in different orientations and can remain readable after some damage through error correction. Its standardized format supports uses from product identification and logistics to mobile links and tickets, although a code's destination still needs to be trustworthy.

Last updated
18 October 2026
Confidence
High (98%)
Sources
8
Versions
2
This article was researched and drafted with AI assistance and checked by an automated review pass. It is not guaranteed to be accurate — verify important facts against the references below.

Development and purpose

QR codes grew out of efforts to improve product identification in manufacturing. Conventional one-dimensional barcodes encode information along a single axis and were commonly used to identify parts, but manufacturers wanted a compact code that could carry more information and be read quickly. A DENSO WAVE team led by engineer Masahiro Hara developed the two-dimensional code, and the company announced its release in 1994. The initials QR stand for “quick response,” referring to the emphasis on rapid reading.

Structure and reading

A QR code is a square matrix of light and dark modules that encode data in two dimensions. Large finder patterns at three corners help a scanner locate the symbol and determine its orientation, so the code can be read even when rotated. A camera or optical scanner captures the pattern; software then decodes it into the information it represents, which may include numbers, text, or a web address. Capacity varies with the symbol's size and encoding mode.

Error correction and standardization

QR codes can include error-correction data based on Reed–Solomon coding. This allows a scanner to recover some encoded information when a symbol is dirty or partly damaged, though it does not make every damaged code readable. The format provides four selectable error-correction levels; stronger correction uses more of the symbol's capacity. The current ISO/IEC 18004:2024 standard specifies QR-code encoding, symbol dimensions, error-correction rules, decoding and production-quality requirements.

Uses and limits

QR codes are used in manufacturing and logistics as well as on tickets, product packaging, menus and digital payment or information services. In the GS1 Digital Link system, a QR code can carry a product identifier and connect a scan to online product information; other QR codes may simply encode text or a URL. The symbol itself does not verify that its contents are safe. The U.S. Federal Trade Commission warns that scammers can replace public codes or send deceptive ones that lead to phishing websites, so readers should check a destination before opening it.

Key facts

Full name
QR stands for Quick Response.
Introduced
DENSO WAVE announced the QR Code in 1994; its development team was led by Masahiro Hara.
Type
A two-dimensional matrix barcode that encodes information across and vertically.
Finder patterns
Three large corner patterns help a scanner locate and orient the symbol.
Error correction
Reed–Solomon coding supports recovery of some data when a symbol is partly damaged.
International specification
ISO/IEC 18004:2024 specifies QR-code symbology and decoding requirements.

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References

  1. 1.
    QR Code

    Encyclopaedia Britannica · other · reliability: high · retrieved 18 October 2026

    Supports: The QR Code's structure, purpose, scanner operation and finder patterns.

  2. 2.
    Error correction feature

    DENSO WAVE · other · reliability: high · retrieved 18 October 2026

    Supports: Reed–Solomon error correction and the four selectable correction levels.

  3. 3.
    History of QR Code

    DENSO WAVE · other · reliability: high · retrieved 18 October 2026

    Supports: The motivation, development, 1994 release, name and early adoption of the QR Code.

  4. 4.
    QR Code development story

    DENSO WAVE · other · reliability: high · retrieved 18 October 2026

    Supports: The development team's design objectives and the use of positional detection patterns for fast scanning.

  5. 5.
    ISO/IEC 18004:2024 - Information technology — Automatic identification and data capture techniques — QR code bar code symbology specification

    International Organization for Standardization (ISO) · other · reliability: high · retrieved 18 October 2026

    Supports: Current international specification for QR-code encoding, symbol formats, dimensions, error correction and production quality.

  6. 6.
    Learn about 2D barcodes powered by GS1

    GS1 · other · reliability: high · retrieved 18 October 2026

    Supports: Applications of QR Code and GS1 Digital Link for product identifiers and online product information.

  7. 7.
    What is a QR Code

    GS1 US · other · reliability: high · retrieved 18 October 2026

    Supports: QR codes as two-dimensional matrix barcodes, their orientation-independent scanning and product-identification uses.

  8. 8.
    Scammers hide harmful links in QR codes to steal your information

    U.S. Federal Trade Commission · other · reliability: high · retrieved 18 October 2026

    Supports: The risk that deceptive or substituted QR codes may direct users to phishing sites or malware.

References are suggested by the research engine and may be incomplete. Unverified URLs are omitted rather than guessed.

Article history

  1. Version 218 October 2026 · EditorUpdated by Zapia
  2. Version 118 October 2026 · EditorCreated by Zapia