A number needs
a source.

How we use sources

Specifications come from their authors or maintainers. Product prices and limits come from the vendor's own pages. Research figures retain their population, period and unit. A payment-system total is not relabeled as a QR scan count, and a smartphone ownership figure is not a QR adoption rate.

Worked examples show their chosen inputs and method. Recommendations about placement or layout are editorial guidance, not measured success rates. When a source cannot be read or a currency is ambiguous, we leave the unsupported claim out or mark the limitation beside it.

Last checked: October 29, 2026. This is a research snapshot, not a promise that every external page remains unchanged. Email contact@tidyqr.com with a correction and the relevant primary source.

Source registry

1. QR Code versions and information capacity
   DENSO WAVE. Checked 2026-10-29.
2. Capacity table: versions 1 to 10
   DENSO WAVE. Checked 2026-10-29.
3. Capacity table: versions 11 to 20
   DENSO WAVE. Checked 2026-10-29.
4. Capacity table: versions 21 to 30
   DENSO WAVE. Checked 2026-10-29.
5. Capacity table: versions 31 to 40
   DENSO WAVE. Checked 2026-10-29.
6. Error correction feature
   DENSO WAVE. Checked 2026-10-29.
7. Determining the QR code area
   DENSO WAVE. Checked 2026-10-29.
8. Setting the module size
   DENSO WAVE. Checked 2026-10-29.
9. Micro QR Code
   DENSO WAVE. Checked 2026-10-29.
10. rMQR Code
    DENSO WAVE. Checked 2026-10-29.
11. Barcode Contents
    ZXing project. Checked 2026-10-29.
12. WifiUriParser.java
    Android Open Source Project. Checked 2026-10-29.
13. RFC 6350: vCard Format Specification
    RFC Editor. Checked 2026-10-29.
14. RFC 5545: iCalendar
    RFC Editor. Checked 2026-10-29.
15. RFC 6068: The mailto URI Scheme
    RFC Editor. Checked 2026-10-29.
16. RFC 5724: URI Scheme for SMS
    RFC Editor. Checked 2026-10-29.
17. RFC 3966: The tel URI for Telephone Numbers
    RFC Editor. Checked 2026-10-29.
18. RFC 5870: The geo URI
    RFC Editor. Checked 2026-10-29.
19. BIP 21: URI Scheme
    Bitcoin BIPs contributors. Checked 2026-10-29.
20. EPC069-12 version 3.1
    European Payments Council. Checked 2026-10-29.
21. How to use click to chat
    WhatsApp Help Center. Checked 2026-10-29.
22. Scan a QR code with your iPhone or iPad
    Apple. Checked 2026-10-29.
23. Scan QR codes with your Pixel phone
    Google. Checked 2026-10-29.
24. QR Code Guideline
    REHAU Brand Management. Checked 2026-10-29.
25. Web Content Accessibility Guidelines 2.2
    W3C. Checked 2026-10-29.
26. Scammers hide harmful links in QR codes
    Federal Trade Commission. Checked 2026-10-29.
27. QR Codes: what is the real risk?
    UK National Cyber Security Centre. Checked 2026-10-29.
28. Unsolicited packages containing QR codes used in fraud
    Federal Bureau of Investigation. Checked 2026-10-29.
29. Personal cyber security handbook: spot scams
    Australian Signals Directorate. Checked 2026-10-29.
30. Singapore Quick Response Code
    Monetary Authority of Singapore. Checked 2026-10-29.
31. PayNow Singapore
    Association of Banks in Singapore. Checked 2026-10-29.
32. Implementation specifications, checked against source code
    Tidy QR. Checked 2026-10-29.
33. Free QR Code Generator
    QR Code Generator. Checked 2026-10-29.
34. Plans and pricing
    QR Code Generator. Checked 2026-10-29.
35. Plans and pricing
    QR TIGER. Checked 2026-10-29.
36. Plans and pricing for QR Codes
    Uniqode. Checked 2026-10-29.
37. Pricing
    Flowcode. Checked 2026-10-29.
38. Plans and pricing
    QRCodeChimp. Checked 2026-10-29.
39. QR code pricing
    Hovercode. Checked 2026-10-29.
40. Pricing
    QR.io. Checked 2026-10-29.
41. Premium and free plan
    ME-QR. Checked 2026-10-29.
42. How can I reactivate my QR Codes?
    QRfy. Checked 2026-10-29.
43. Free QR Code Generator
    Canva. Checked 2026-10-29.
44. Adobe Express free QR code generator
    Adobe. Checked 2026-10-29.
45. Share tabs in Chrome
    Google. Checked 2026-10-29.
46. Americans’ Use of Mobile Devices in 2026
    Pew Research Center. Checked 2026-10-29.
47. Economic Survey 2025-26 Statistical Appendix, table 3.6
    Government of India, Economic Survey, source NPCI. Checked 2026-10-29.
48. SI Units: Length
    National Institute of Standards and Technology. Checked 2026-10-29.
49. Tips to get more reviews
    Google. Checked 2026-10-29.