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Bug: QR code generated with error correction level L, unreadable when printed small #659
Description
Bug Report: QR Code Error Correction Level L Causes Scan Failures in Print
Description
DevCard QR codes are generated using the default error correction level L
(7% data recovery). When the QR code is printed in a small format (e.g., on
a business card at 3cm x 3cm) or displayed on a low-resolution screen, even
minor smudging, pixelation, or partial occlusion (a logo overlay, a coffee
stain) makes the code unscannable. Level M (15%) or Q (25%) provides
substantially better real-world reliability at minimal size cost.
Steps to Reproduce
- Generate a DevCard QR code for a user.
- Print it at business-card scale (approximately 3cm x 3cm).
- Attempt to scan the printed code under non-ideal lighting.
- Observe scan failures that do not occur on the digital version.
Root Cause
The QR generation library is called without specifying an error correction
level, defaulting to L.
Impact
The primary sharing mechanism (QR code at physical events, conferences, on
printed business cards) is unreliable, directly undermining the product's
core value proposition.
Proposed Fix
Set error correction to M or Q in the QR generation call:
import QRCode from "qrcode";
const qrDataUrl = await QRCode.toDataURL(devCardUrl, {
errorCorrectionLevel: "M", // Recovers up to 15% damage
margin: 2,
width: 256,
});Metadata
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github-actions commentedon Jul 3, 2026
Hi @anshul23102,
anshul23102 commentedon Jul 3, 2026
@Dev-Card Hi! I came across this issue and I would love to work on it as part of GSSoC '26.
I have reviewed the problem description carefully and am confident I can deliver a well-tested, production-ready fix within the contribution timeline. Please let me know if you need any additional context or have specific implementation preferences before I get started.
Could you please assign this issue to me?
/assign
/claim
anshul23102 commentedon Jul 3, 2026
Hi @Dev-Card, I'd like to work on this as part of GSSoC '26.
The issue is accurate — error correction level L (7% recovery) is too weak for small prints. Level M (15%) or Q (25%) adds negligible size overhead but provides real robustness. A simple one-line change to the QR generation library call.
I can update the code and test with various print sizes to confirm readability improves.
/assign
/claim
Harxhit commentedon Jul 15, 2026
@anshul23102 I have assigned this issue to you.