QR Code FAQ
Frequently Asked Questions About QR Codes, Barcodes, and Scanning
Welcome to the QR Codex FAQ. Here you’ll find quick, reliable answers to the questions we hear most often. If you don’t see what you’re looking for, feel free to reach out via our Support page.
General
What is QR Codex?
QR Codex is an educational platform that provides clear, human-friendly explanations of QR codes, barcodes, scanning systems, and related technologies.
Is the content free?
Yes. All informational materials, guides, and explanations are free to read.
QR Codes
How do QR codes work?
A QR code stores binary data in a two-dimensional matrix. When scanned, the device reads the module pattern, applies error correction, and decodes the content into text, URLs, or other formats.
What can a QR code store?
QR codes can store short text, URLs, contact cards, Wi-Fi credentials, email templates, SMS messages, calendar events, and geographic coordinates—up to roughly 3 KB.
Why won’t my QR code scan?
Typical reasons include low contrast, poor print quality, small size, reflective surfaces, damaged modules, or insufficient lighting.
Do QR codes expire?
Static QR codes do not expire. Dynamic QR codes can change or be deactivated depending on the service provider.
Barcodes
Are QR codes the same as barcodes?
No. Barcodes are one-dimensional and store data using bars and spaces. QR codes are two-dimensional and can store more data with higher fault tolerance.
What barcode type should I use?
For retail: UPC or EAN.
For logistics: Code 128 or Code 39.
For books: ISBN/EAN-13.
Each standard serves a specific purpose.
Scanning & Equipment
Do smartphones need apps to scan QR codes?
Modern iOS and Android phones can scan QR codes using the built-in camera. Dedicated scanning apps offer additional features.
Which QR scanner app is recommended?
Reliable options include:
- i-nigma
- Google Lens
- Native Camera App (iOS)
Why do some scanners read faster than others?
Differences in camera quality, decoding algorithms, autofocus speed, and error-correction implementation.
Using QR Codex
Can I request new articles or tutorials?
Yes. Visit the Support page to send us topic suggestions.
Can I quote your content?
Yes, as long as you include attribution.
If your question is not answered here, we’re always happy to help — just visit our Support page.