Blame for README.md

---
title: QR Scan Difficulty
emoji: 📷
colorFrom: green
colorTo: red
sdk: static
pinned: false
license: other
short_description: Not every phone reads the same QR codes, measured
---

# Not every phone reads the same QR codes

A one-page answer to "will this QR code scan?", for people who know why QR codes matter but don't
have time for a dashboard. Every number comes from measured decodes.

Every iPhone, about 1 in 4 smartphones in use, has the same scanner: Apple's, which read 69% of our
6,499 test codes. On the other 3 in 4, more than 3 billion phones, the scanner depends on the maker
and the app, and the scanners Android phones come with read from 42% to 68%:

- **Samsung's own**, in its Camera app ([Samsung's guide](https://www.samsung.com/us/support/answer/ANS10001925/)),
  on more than a billion phones: about 59%, measured on a real Galaxy A57 from a sample of the codes. It
  misses about 15 of every 100 codes an iPhone reads.
- **Google's ML Kit**, which Android's own QR button (lock screen and Quick Settings) opens, as on Pixel phones
  ([Android's source](https://android.googlesource.com/platform/frameworks/base/+/refs/heads/main/core/java/com/android/internal/config/sysui/SystemUiDeviceConfigFlags.java):
  "On the eligible devices this activity is provided by GMS core"): 61%.
- **Huawei's Scan Kit**, built into Huawei phones
  ([HarmonyOS](https://developer.huawei.com/consumer/en/doc/harmonyos-guides/scan-introduction),
  [HMS Core](https://developer.huawei.com/consumer/en/doc/development/HMSCore-Guides/service-introduction-0000001050041994)): 68%.
- **ZXing**, which [Android's Settings app](https://cs.android.com/android/_/android/platform/frameworks/base/+/2ecfdb1d2dd832c637aacfa15c257822b94f10b1:packages/SettingsLib/src/com/android/settingslib/qrcode/QrCamera.java;bpv=1;bpt=0)
  uses for Wi-Fi codes only: 42%.
- **Apps** bring their own; the four open-source scanners apps are built on read 27% to 67%.

The built-in scanners of more than 1 in 3 phones, from Xiaomi, OPPO, vivo, Transsion and Honor,
could not be measured.

Phones in use: [Counterpoint Research](https://counterpointresearch.com/en/insights/Active-Installed-Base-8-Smartphone-OEMs-Top-200-mn-Nearly-1-in-4-is-an-iPhone),
active smartphones in 2025: "nearly one in four active smartphones is an iPhone, while nearly one in five
is a Samsung"; only Apple and Samsung pass a billion, and eight makers have more than 200 million each.
People: at the end of 2025, 4.6 billion, 56% of the world, went online with a smartphone of their own
([GSMA, State of Mobile Internet Connectivity 2026](https://www.gsma.com/somic/wp-content/uploads/2026/09/The-State-of-Mobile-Internet-Connectivity-2026.pdf), p. 32).
Web counters such as StatCounter show iPhones higher, about 31% of mobile page views, because they
count page views, not phones.

1. **Not every phone reads the same QR codes.** Each scanner's share of all the codes, and what the
   gap means for one code.
2. **The QR code was invented for messy factories.** Why the gap matters: Denso made the QR code in 1994
   for oily, damaged factory labels, with error correction built in, in the words of its developer,
   Masahiro Hara. When one scanner reads a picture and another misses it, the difference is the software.
3. **More than a billion phones read fewer codes than an iPhone.** Which phones use which scanner,
   how many phones that is, how many codes each reads, and how many of every 100 codes an iPhone
   reads it misses (and reads that the iPhone misses).
4. **The gap opens on harder codes.** One strip per set of codes (clean, everyday, tough, hardest
   cases) at a chosen image resolution: 1920, 1280 or 640 pixels on the long side. Samsung's estimate
   appears at 1280, the one resolution it was read at.
5. **Even everyday prints fail on some scanners.** Every tested code on one scale from easy to
   hard, shaded by how many of the eight scanners read it. Drag along it to see a code from that
   spot, and the mix of shades there; a link under the code opens its exact picture, to try with your
   own phone.
6. **What makes a code hard to read.** Six before-and-after pairs (small squares, too much data for
   the size, blur, faded ink, tight curves, a covered corner square), each with the scanners that still
   read it. The data pair shows the same version 21 codes squeezed into a small space and printed
   bigger: more data needs a bigger print, because its squares shrink in the same space.
7. **What helps a code scan on every phone.** Five plain rules, each backed by the measurements.

Everything else waits behind a "+", for readers who want to master it: each scanner's full profile;
how a scanner reads a QR code (telling dark from light, finding the corner squares, fitting the grid, reading
the squares, error correction) and, for each of the 17 factors, the step it breaks; and how the
measurements were made.

## Decoders

| On the page | Decoder | What it is | Version |
|---|---|---|---|
| Apple's scanner | [Apple Vision](https://developer.apple.com/documentation/vision/vndetectbarcodesrequest) | Apple's barcode detector, built into iOS; our stand-in for the iPhone, measured on a Mac | macOS 14.3, `VNDetectBarcodesRequest` revision 4 |
| Google's scanner | [ML Kit](https://developers.google.com/ml-kit) ([barcode scanning](https://developers.google.com/ml-kit/vision/barcode-scanning)) | Google's barcode scanner as Google Play services delivers it; on Google's Android 14 image, Android's QR button is set to Play services' ML Kit barcode scanner | play-services-mlkit-barcode-scanning 18.3.1 with Google Play services 26.41.31 (barcode module 264131001), QR only, on Google's Android 14 emulator image (API 34, arm64) |
| Samsung's scanner | [Samsung Camera's QR scanner](https://www.samsung.com/us/support/answer/ANS10001925/), with a decoder by [Quram (Quramsoft)](https://www.quramsoft.com/) | the scanner in Samsung's Camera app, which the "Scan QR code" button in Quick Settings opens on Samsung phones; read on a real phone borrowed through Samsung's Remote Test Lab, on a random sample of the codes | Camera 16.5.00.85 on a Galaxy A57 (SM-A576S), One UI 8.5, Android 16; each picture opened from the gallery, at 1280 px only |
| Huawei's scanner | [Huawei Scan Kit](https://developer.huawei.com/consumer/en/hms/huawei-scankit/) | Huawei's scanning engine, built into HarmonyOS and shipped in HMS Core on Huawei phones; the kit's three models are byte-identical to those in HMS Core 6.16.2.300 | `com.huawei.hms:scanplus` 2.15.0.301 from Huawei's developer repository, photo mode (`decodeWithBitmap`), QR only, on Google's Android 14 emulator image (API 34, arm64) |
| Android Settings' scanner | [ZXing (Java)](https://github.com/zxing/zxing/releases/tag/zxing-3.5.2) | the scanner Android's Settings app uses for Wi-Fi codes; also inside apps built on zxing-android-embedded | 3.5.2, called as AOSP's `QrCamera` calls it, inverted retry included |
| WeChat's scanner | [WeChat](https://docs.opencv.org/4.12.0/d5/d04/classcv_1_1wechat__qrcode_1_1WeChatQRCode.html) | WeChat's neural-network scanner, open-sourced in OpenCV (the app's own build may differ) | OpenCV contrib 4.12 with its detector and super-resolution models |
| zxing-cpp | [zxing-cpp](https://github.com/zxing-cpp/zxing-cpp/releases/tag/v3.1.1) | grew out of ZXing; used by open-source Android scanners such as Binary Eye | 3.1.1, library defaults |
| OpenCV, newer | [OpenCV ArUco](https://docs.opencv.org/4.12.0/d3/db0/classcv_1_1QRCodeDetectorAruco.html) | OpenCV's ArUco-based QR detector | 4.12 `QRCodeDetectorAruco`, single-code `detectAndDecode` |
| OpenCV, original | [OpenCV](https://docs.opencv.org/4.12.0/de/dc3/classcv_1_1QRCodeDetector.html) | OpenCV's first QR detector | 4.12 `QRCodeDetector`, single-code `detectAndDecode` |

An iPhone has one built-in scanner that the Camera and any app can use. Android ships none for
everyday codes: its QR button opens one that Google or the phone maker supplies, camera apps use the
maker's own (Samsung's in its Camera app; Huawei's is Scan Kit), and every other app picks its own, so the same code can
scan in one app and fail in another.

Google's scanner is measured as Google Play services delivers ML Kit, on Google's Android 14 emulator
image, where the QR button's default is `com.google.android.gms/.mlkit.barcode.ui.PlatformBarcodeScanningActivityProxy`.
The model lives in Play services' barcode module, which updates with Play services. The image's Play Store
updated Play services to 26.41.31 (October 2026) by itself; that version was then held for the whole
measurement, and every result records the versions of Play services and its barcode module. On Google's
images for each Android version, every up-to-date one from Android 9 to 17 read every code exactly the same;
older Play services read a little less (57% of codes with 2023's version).

Huawei's scanner is measured through Huawei's own developer kit, on the same emulator image, reading
each picture in the kit's photo mode. The kit's camera mode, meant for live video frames, read a
little less of these still pictures.

Samsung doesn't name the decoder in its scanner, but the phone shows whose it is: the Camera app decodes
with a library that carries the name of [Quram](https://www.quramsoft.com/), a Korean imaging-software company,
and the decoding engine names itself in the phone's log. Quram sells a QR and barcode scanner of its own and
names Samsung among its customers.

Samsung's scanner runs only on Samsung phones, so it was read on a real Galaxy A57 borrowed through
[Samsung's Remote Test Lab](https://developer.samsung.com/remote-test-lab), on a random sample of each set at
1280 px. Each picture was opened from the phone's gallery in the scanner, inside a white border, because the
crop box the gallery shows first keeps only the middle of a picture. A read is the text on its result card, equal
to the code's content. Some content it never shows as text: it hands contacts, Wi-Fi, calendar, SMS, location,
email and phone codes and Facebook links straight to an app (its log names each action), and shows binary content and
JSON text as an empty card. Codes with such content are left out of its comparison, for every scanner. Its
figures are estimates: its gap to the other scanners on the codes it read, added to their results on all of a
set's codes. On all codes that comes to about 59% (57% to 61%, 95% confidence).

Not yet measured: the scanners other phone makers build into their phones, such as Xiaomi's, OPPO's,
vivo's, Transsion's and Honor's. Each runs only on its maker's phones, so it can be measured only on real devices
borrowed from a test lab, far more slowly than the other scanners. Samsung's came first, for its more than a billion
phones, and even it on a sample of the codes; the others are left for future work.

## Codes

- **Made here** (synthetic captures, payloads made up): pristine, everyday and tough tiers, plus
  one-factor ladders: a code all eight scanners read, changed one step at a time, 80 codes per step,
  each code the same at every step but for the factor. One ladder, "More data, printed bigger", takes
  the amount-of-data ladder's own codes and keeps every square at 6 camera pixels, up to version 21.
  Published as
  [QR Scan Difficulty: synthetic codes](https://huggingface.co/datasets/devmandan/qr-scan-difficulty),
  with each code's content, every setting used to make it, and which scanners read it.
- **Research datasets**, each used under its own terms. Most of their codes are the page's "hardest cases": codes
  researchers collected or built to copy the toughest conditions real codes meet. The other 1,525 are easy, QR-DN1.0's
  clean originals, alone or tiled four to a picture.
  - [BoofCV QR singles](https://huggingface.co/datasets/devmandan/boofcv-qr-singles): Peter Abeles'
    BoofCV QR Code Performance Benchmark photos, published openly without an explicit licence grant.
  - [QR-DN1.0](https://huggingface.co/datasets/devmandan/qr-dn1.0): clean QR codes, the same codes
    tiled four to a picture, and distorted, noisy versions of them; CC BY 4.0 (Mendeley Data,
    doi:10.17632/t2bdr663ms.2).
  - [syn10k](https://huggingface.co/datasets/devmandan/syn10k-huawei-barcodes): Bodnár, Grósz and
    Tóth's barcode images; the page uses 1,000 of its computer-made warped ones. CC BY 4.0.
  - [Broken QR 104](https://huggingface.co/datasets/devmandan/broken-qr-codes-104): real codes that
    fail to decode, collected from public web sources; annotations CC BY 4.0.

A code in an image can be read by any phone, so showing an image shows its payload. Images are
cropped and resized from their datasets; to have one removed, open a discussion on its dataset
page. The page itself never prints payload text.

## How it was measured

Every image is read at seven image resolutions, 1920 down to 224 pixels on the long side: larger
images are shrunk to each size, smaller ones are read as they are, never enlarged. Most
research-dataset images are 512 × 512, so only the sizes below 640 shrink them. Every decoder reads
every image at every size, and a two-parameter item-response model turns the pattern of reads and
misses into one difficulty per code. The ladders are read at 1280 px.

A read counts only when a scanner returns the code's exact content, byte for byte; finding a code
without reading it is a miss. The content comes with each code: made here, or published by its
dataset. BoofCV's photos and QR-DN (whose distorted images take the content of their clean
originals) come without it; there the content is what other decoders read identically, and a code
is kept only when at least two decoders other than the scanner being scored agree, which leaves out
4 photos. On 100 images with no code, made to fool scanners (look-alike corner squares,
checkerboards, clutter, other barcode types), none of the eight returned anything. Samsung's scanner
read them on its phone with no false readings; among the other barcode types it read the 4 Data Matrix
codes, each correctly, as it reads Data Matrix as well as QR codes (the eight, as we ran them, read QR
codes only).

One rule throughout: a code's shade counts the scanners that read it at 1280 px (all eight, most =
5 to 7, some = 1 to 4, none). A group of codes, such as a ladder step or a set, counts a scanner when
it reads at least 9 in 10 of them. The page's "How we measured" section has the details.

## Why we made this

To show how unevenly the world's phones read QR codes, and to help everyone who builds a scanner see where
theirs falls short and improve it. A measurement this broad has become practical only recently, thanks to AI
models that help write the software behind it.

## Disclosures

Independent work, not affiliated with or endorsed by any company or organization named here: Apple, Google,
Samsung, Quram (Quramsoft), Huawei, Honor, Xiaomi, OPPO, vivo, Transsion, Tencent, Meta, Denso, DENSO WAVE,
Toyota, GS1, Counterpoint Research, GSMA, ITU, IDC or StatCounter; nor by the open-source projects and dataset
authors credited above. QR Code is a registered trademark of DENSO WAVE INCORPORATED. Apple and iPhone are
trademarks of Apple Inc.; Android, Google Play, ML Kit and Pixel of Google LLC; Samsung and Galaxy of Samsung
Electronics Co., Ltd.; Huawei and HarmonyOS of Huawei Technologies Co., Ltd.; WeChat of Tencent; WhatsApp and
Instagram of Meta Platforms, Inc. Other names are trademarks of their owners.