# iQR

> Source: https://docs.barcoder.ai/docs/standards/iqr
> research date 2026-05-30 · extracted at 2026-10-04
> Publisher: Barcoder — encyclopedia of QR, barcode and payment-code standards

Specifications:
- [iQR Code — Denso Wave](https://www.qrcode.com/en/codes/iqr.html)
- [Denso Wave introduces iQR Code — Denso press](https://www.denso-am.eu/news/denso-wave-introduces-a-new-rectangular-qr-code)

## Overview

> **Note on classification.** This entry was originally bucketed as a QR standard, but iqr is **not a QR-symbol standard** — it is a generic 2D matrix symbology (not a payment QR). Reclassified as `2D Matrix`. The wiki shows no playground because there is no QR payload to encode; the slug is retained to avoid breaking incoming links.

**iQR Code** is a **2D matrix barcode symbology** developed by **Denso Wave in 2008** as a **smaller-footprint, rectangular-shape variant of [QR Code](https://docs.barcoder.ai/docs/standards/qr-code)** <sup>[1][1], [2][2]</sup>. Unlike standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) (which is always square) and [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr) (small square), iQR can be **either square OR rectangular**, with the rectangular variant specifically designed for **cylindrical objects, narrow labels, and tight-aspect-ratio surfaces** where a square QR doesn't fit well <sup>[1][1], [3][3]</sup>. iQR codes fit **the same amount of information in 30 % less space** than standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) <sup>[1][1]</sup>.

A defining feature: iQR adds a fourth error-correction level **S** ("Super") on top of the standard L/M/Q/H, enabling **50 % damage tolerance** — the highest of any QR-family symbology <sup>[1][1]</sup>. **Note on standardisation**: as of 2015, iQR had **not been given an ISO/IEC specification** <sup>[1][1]</sup>, meaning **only proprietary Denso Wave products could create or read iQR codes**. This contrasts with standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) and [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr), which are both in ISO/IEC 18004.

## History

**Background — Denso Wave's QR family expansion** <sup>[2][2], [qr-code-ref]</sup>:
- 1994: **Standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code)** (square, omnidirectional) invented by Denso Wave for automotive parts tracking.
- 2004: **[Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr)** introduced for small-footprint applications.
- 2008: **iQR Code** introduced for narrow / rectangular spaces.
- Later: **rMQR Code** (rectangular Micro QR), **SQRC** (Secure QR), **Frame QR** (QR with central design region).

The pattern: Denso Wave maintains a **family of QR variants** for specific deployment niches, all sharing the QR brand but with structural differences for particular use cases.

**2008 — iQR Code launch** <sup>[2][2], [1][1]</sup>: Denso Wave released iQR Code primarily for industrial deployment contexts where standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) didn't fit:
- **Cylindrical objects** (cables, pipes, small components) — rectangular shape aligns with curvature better than square.
- **Narrow labels** — e.g., medical syringes, small adhesive labels where vertical space is constrained.
- **High-density data on small surfaces** — 30 % space savings vs standard QR.

**Patent and licensing status** <sup>[1][1]</sup>: iQR Code, like its parent [QR Code](https://docs.barcoder.ai/docs/standards/qr-code), is in the **public domain** for use — Denso Wave released the patents royalty-free. However, the **ISO/IEC standardisation status** is the structural issue: **as of 2015, only proprietary Denso Wave products could create or read iQR codes**, limiting third-party library adoption.

**ISO standardisation status** <sup>[1][1]</sup>: iQR's continued absence from ISO/IEC 18004 (which covers standard QR and Micro QR) means **iQR has a much smaller library and scanner-support ecosystem** than its better-known siblings. This is the load-bearing reason iQR adoption has been slow despite its technical advantages.

**Continued use** <sup>[2][2], [3][3]</sup>: iQR is in **active industrial use in Japan and select export contexts** — particularly automotive, electronics, and medical-device direct-part marking where rectangular footprint matters. Outside these niches, adoption has been limited.

## Technical specification

iQR Code is a **2D matrix symbology with both square and rectangular forms** <sup>[1][1], [3][3]</sup>:

| Parameter | Value |
|---|---|
| Symbol shape | **Square OR rectangular** (the rectangular option is distinctive) |
| Square versions | Multiple sizes (similar to standard QR) |
| Rectangular versions | **R1 to R15** — from 5×19 to 43×131 modules |
| Capacity (min, R1) | 6 numerals |
| Capacity (max, R15) | ~1 200 characters |
| Encoding modes | Numeric, alphanumeric, byte, kanji |
| Error correction | **Reed–Solomon**, **four levels: L / M / Q / H plus new S** |
| **Error correction level S** | **50 % damage tolerance** — highest of any QR-family code |
| Standard | **Not in ISO/IEC 18004 (as of 2015)**; defined in Denso Wave SPQR-0004 |

**Rectangular dimensions** <sup>[1][1]</sup>:

| Version | Module dimensions | Approx capacity |
|---|---|---|
| **R1** (smallest) | **5 × 19 modules** | 6 numerals |
| ... | ... (15 sizes total) | ... |
| **R15** (largest) | **43 × 131 modules** | ~1 200 characters |

**Space efficiency** <sup>[1][1]</sup>: iQR encodes equivalent payload in **~30 % less area** than standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code), achieved through:
- **Reduced overhead modules** (fewer finder patterns and version-info modules in some configurations).
- **Optimised data layout** for rectangular shapes.
- **Compact version sizing** with smaller increment steps between versions.

**Error correction level S** <sup>[1][1]</sup>: iQR's unique addition to the standard L/M/Q/H levels. Provides **50 % damage tolerance** — useful for industrial direct-part marking where mechanical wear and chemical exposure are constant. **Higher EC than [QR Code](https://docs.barcoder.ai/docs/standards/qr-code)'s maximum H (30 %), [Data Matrix](https://docs.barcoder.ai/docs/standards/data-matrix)'s ECC 200 (~30 %), [Aztec](https://docs.barcoder.ai/docs/standards/aztec)'s maximum (~95 % nominal but typically 25–50 % in practice)**.

**Structural differences from standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code)** <sup>[1][1]</sup>:
- Rectangular shape option (standard QR is always square).
- Smaller overhead allocation (more area for data).
- Additional EC level S.
- Not (yet) in ISO/IEC 18004.

## Use cases

iQR's use cases concentrate on **industrial direct-part marking where rectangular footprint matters** <sup>[2][2], [3][3]</sup>:

- **Cylindrical objects** — cables, pipes, hoses, narrow components. The rectangular long-thin shape aligns with the surface curvature better than square QR's footprint.
- **Medical syringes and ampoules** — narrow surface where rectangular labels fit naturally.
- **Electronic component direct-part marking** — small PCB components, cable connectors, narrow heat sinks.
- **Automotive narrow components** — hose clamps, narrow brackets, cylindrical fasteners.
- **Industrial micro-marking** where standard QR or Micro QR can't fit the required data into the available space.

**Why iQR is rarely chosen over alternatives** <sup>[1][1]</sup>:
- **ISO/IEC standardisation gap** — third-party libraries and scanners don't always support iQR (compared with universal [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) / [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr) support).
- **[Data Matrix](https://docs.barcoder.ai/docs/standards/data-matrix)'s installed-base advantage** in industrial direct-part marking.
- **[Code 128](https://docs.barcoder.ai/docs/standards/code-128) still dominant** for cylindrical-object labelling where 1D suffices.
- **rMQR** (rectangular Micro QR, Denso Wave's later 2022 release) is a similar concept with newer hardware support; some applications choosing rMQR over iQR.

**Where iQR uniquely wins** <sup>[1][1], [3][3]</sup>:
- **Industrial contexts where rectangular shape is required AND high EC (level S) is needed** — i.e., narrow cylindrical surfaces with mechanical-wear exposure.
- **Japanese industrial contexts** where Denso Wave's brand recognition and direct support are advantages.

iQR Code has **substantially narrower library and scanner support** than [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) / [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr) because of its absent ISO/IEC standardisation <sup>[1][1]</sup>. Documenting the gap is itself useful: every popular open-source QR library checked below stops at ISO/IEC 18004 (standard QR + Micro QR) and does **not** ship an iQR encoder or decoder.

**Open-source QR libraries — iQR support status** (none of these implement iQR; listed because they are the libraries developers reach for first and then discover iQR is missing):

| Repo | Language | Stars | License | Last release | Supports iQR? |
|---|---|---:|---|---|---|
| [nayuki/QR-Code-generator](https://github.com/nayuki/QR-Code-generator) | Java / TS / JS / Python / Rust / C++ / C | 6,600 | MIT | v1.8.0, Apr 2022 | **No** — ISO/IEC 18004 Model 2 only <sup>[8][8]</sup> |
| [fukuchi/libqrencode](https://github.com/fukuchi/libqrencode) | C | 2,900 | LGPL-2.1 | v4.1.1, Sep 2020 | **No** — standard QR only <sup>[9][9]</sup> |
| [heuer/segno](https://github.com/heuer/segno) | Python | 782 | BSD-3-Clause | v1.6.6, Mar 2025 | **No** — ISO/IEC 18004 + Micro QR <sup>[10][10]</sup> |
| [paulmillr/qr](https://github.com/paulmillr/qr) | TypeScript | 339 | MIT / Apache-2.0 | v0.6.0, Apr 2026 | **No** — generic QR encoder + reader |
| [OUDON/rmqrcode-python](https://github.com/OUDON/rmqrcode-python) | Python | — | — | active | **No** — handles **rMQR** (the 2022 ISO-standardised cousin), not iQR |

**Where iQR is actually implemented** (commercial / proprietary):
- **Denso Wave's own SDKs** — the canonical iQR encoder/decoder source.
- **Commercial barcode toolkits** — **Dynamsoft Barcode Reader**, **Aspose.BarCode**, **LEADTOOLS**, **Inlite ClearImage** — typically iQR sits behind enterprise licensing.
- **Industrial 2D scanners** — Cognex, Datalogic, Honeywell, Keyence, Omron, SICK ship iQR-capable firmware in high-end imager lines (especially Japan-market SKUs).
- **Mobile capture SDKs** — Scanbot, Scandit, Anyline list iQR among their supported symbologies on a per-tier basis; consumer iOS/Android system QR readers do **not** decode iQR.

The structural consequence: **without ISO/IEC standardisation, the long tail of open-source mobile-camera QR readers (every iOS / Android phone's built-in QR scanner) does not reliably decode iQR**, which has confined adoption to industrial supply chains where the deployment can mandate compatible scanner hardware.

**Reference documentation** <sup>[2][2], [3][3]</sup>:
- [Denso Wave iQR Code page][2] — primary source.
- Denso Wave SPQR-0004 iQR Code Specification — formal specification, gated.

## Comparison

**vs. [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) (standard QR)** — iQR is a Denso Wave family variant of QR. Differences:

| Dimension | Standard QR | iQR |
|---|---|---|
| Shape | Square only | **Square or rectangular** |
| Sizes | 21×21 to 177×177 (square) | R1 (5×19) to R15 (43×131) rectangular + square variants |
| ISO standardisation | **ISO/IEC 18004** | **Not in ISO/IEC 18004 (as of 2015)** — Denso Wave SPQR-0004 |
| Library support | Universal | **Limited** — Denso Wave SDK + select commercial libraries |
| Error correction levels | L / M / Q / H | L / M / Q / H + **S (50 %)** |
| Space efficiency | Baseline | **~30 % less area** for same data |
| Primary use | Consumer-facing, marketing, payment | Industrial direct-part marking, narrow components |

The structural choice between standard QR and iQR is driven by: **shape constraint** (rectangular required → iQR; square fine → standard QR) and **library / scanner support requirement** (mass-market consumer → standard QR; controlled industrial → iQR acceptable) [[qr-code-ref]].

**vs. [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr)** — Both are Denso Wave QR family variants for smaller footprints. Differences:
- Micro QR: **square only**, very small versions (M1–M4, 11×11 to 17×17 modules), **in ISO/IEC 18004**.
- iQR: **square or rectangular**, larger version range (up to 43×131 modules), **not in ISO/IEC 18004 as of 2015**.

Micro QR wins on **standardisation + universal small-square use case**; iQR wins on **rectangular shape need** [[micro-qr-ref]].

**vs. [Data Matrix](https://docs.barcoder.ai/docs/standards/data-matrix)** — The dominant industrial 2D matrix competitor. Data Matrix is **standardised (ISO/IEC 16022) with universal library support**; iQR has **rectangular shape option but limited library support**. For most industrial direct-part marking, Data Matrix is the safer choice due to library availability; iQR is chosen when the **specific cylindrical / narrow shape requirement** outweighs the standardisation gap [[data-matrix-ref]].

**vs. rMQR Code** (Denso Wave's 2022 rectangular Micro QR) — Newer Denso Wave variant. Similar concept to iQR (rectangular, smaller footprint) but with **better library support and newer industry adoption**. Some applications that would historically have chosen iQR now choose rMQR.

**vs. [Aztec](https://docs.barcoder.ai/docs/standards/aztec)** — Both 2D, both have high error correction options. Aztec is **standardised (ISO/IEC 24778) with broad scanner support** and dominates printed-ticket / boarding-pass deployments. iQR's industrial-cylindrical-surface niche doesn't overlap with Aztec's printed-document-narrow-finder-pattern niche [[aztec-ref]].

## Fun facts

**iQR Code is one of the few QR-family standards NOT in ISO/IEC 18004** <sup>[1][1]</sup> — a structural decision by Denso Wave that has substantially limited iQR's third-party adoption. Standard [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) and [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr) are both in ISO/IEC 18004; iQR remains in **Denso Wave SPQR-0004** (a proprietary specification document). The implication: **library and scanner vendors must license or independently implement iQR**, while standard QR support is "automatic" via ISO compliance. This is a clear cautionary tale about the importance of international standardisation for symbology adoption.

**Error correction level S (50 % damage tolerance)** <sup>[1][1]</sup> is the **highest damage tolerance of any QR-family code**. Most QR symbologies max out at ~30 % (standard QR's Level H, Data Matrix ECC 200). iQR's Level S is structurally important for industrial deployments where the printed surface is subjected to:
- Mechanical wear (cylindrical components rubbing against neighbours).
- Chemical exposure (cleaning fluids, oils, lubricants).
- Heat / cold cycling (engine parts, refrigeration components).
- Long deployment lifetime (parts in service for decades).

**The 30 % space savings vs standard QR** <sup>[1][1]</sup> is achieved through **optimised overhead** — iQR's reduced finder patterns and version-info modules dedicate more area to data. For applications where every square millimetre of label real estate matters, this is structurally significant.

**Denso Wave's QR family strategy** — maintaining multiple QR variants (Standard QR, Micro QR, iQR, rMQR, SQRC, Frame QR) for specific deployment niches — is **the broadest single-brand 2D symbology family in industry** <sup>[2][2]</sup>. The strategic logic: keeping all variants under the QR brand preserves consumer familiarity ("a QR-like code") while enabling technical optimisation for each niche. The trade-off: spreading Denso Wave's engineering and standardisation effort across many variants has meant some variants (like iQR) get less ISO-standardisation attention than others.

**Adoption of iQR has been concentrated in Japan and select Japanese-multinational supply chains** <sup>[2][2]</sup>. Japanese automotive (Toyota, Honda) and electronics (Sony, Panasonic) supply chains use iQR in direct-part marking where the rectangular shape fits the component. Western industrial deployments more commonly choose [Data Matrix](https://docs.barcoder.ai/docs/standards/data-matrix) for the same use case because of better library / scanner support outside Japan.

## Status

**Active, niche-deployed, library-support-limited** <sup>[1][1], [2][2]</sup>:

- **Denso Wave SPQR-0004 specification** is the canonical source.
- **Not in ISO/IEC 18004** (as of 2015 status; check ISO updates for recent changes).
- **Denso Wave + select commercial library support** — much narrower than [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) / [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr).
- **Industrial scanner support** in high-end 2D scanner lines.
- **Public domain** — no licensing fees for use.

**Strategic context**:
- **Newer Denso Wave variants (rMQR Code, 2022)** are picking up some of the rectangular-QR niche iQR was designed for.
- **[Data Matrix](https://docs.barcoder.ai/docs/standards/data-matrix) remains the safer choice** for industrial direct-part marking outside Japan due to ISO/IEC 16022 standardisation and universal library support.
- **iQR's continued use is concentrated in Japanese-origin industrial supply chains** where Denso Wave's brand and direct support are advantages.
- **No deprecation planned by Denso Wave**; iQR remains part of the QR family.

The structural pattern: iQR is **a technically-interesting Denso Wave variant whose adoption is constrained by the absent ISO/IEC standardisation** that its sibling [QR Code](https://docs.barcoder.ai/docs/standards/qr-code) / [Micro QR](https://docs.barcoder.ai/docs/standards/micro-qr) enjoy.

## Sources

[1]: https://en.wikipedia.org/wiki/QR_code
[2]: https://www.qrcode.com/en/codes/iqr.html
[3]: https://www.denso-am.eu/news/denso-wave-introduces-a-new-rectangular-qr-code
[4]: https://barcodeguide.seagullscientific.com/Content/Symbologies/iQR.htm
[5]: https://www.denso-wave.com/en/adcd/info/detail__220525.html
[6]: https://qrlynx.com/blog/iso-iec-18004-qr-code-standard-explained
[7]: https://orquitool.com/en/blog/history-of-qr-codes/
[8]: https://github.com/nayuki/QR-Code-generator
[9]: https://github.com/fukuchi/libqrencode
[10]: https://github.com/heuer/segno
[qr-code-ref]: https://docs.barcoder.ai/source/standards/qr-code
[micro-qr-ref]: https://docs.barcoder.ai/source/standards/micro-qr
[data-matrix-ref]: https://docs.barcoder.ai/source/standards/data-matrix
[aztec-ref]: https://docs.barcoder.ai/source/standards/aztec

1. [QR code (incl. iQR) — Wikipedia][1]
2. [iQR Code — Denso Wave][2]
3. [Denso Wave introduces iQR Code — Denso press][3]
4. [iQR Code — Seagull Scientific BarTender][4]
5. [rMQR Code — Denso Wave][5]
6. [ISO/IEC 18004 QR Code Standard — QRLynx][6]
7. [History of QR Codes — Orquitool][7]
8. [nayuki/QR-Code-generator — GitHub][8]
9. [fukuchi/libqrencode — GitHub][9]
10. [heuer/segno — GitHub][10]

## Deployments

_No country reports mention this standard by name._

## Regions / aggregations not mapped to a single country

- Universal