What is a QR Code?
QR Code (Quick Response Code) is a two-dimensional barcode that can store URLs, text, contact information, and various data types. Scan with a smartphone camera to quickly access content. Widely used in marketing materials, business cards, product packaging, event registration, and more. Combine with UTM Builder to track traffic from QR codes.
QR Code Technical Specifications
Understanding QR code technical parameters helps you choose the right settings:
Error Correction Level
QR codes have 4 error correction levels that determine readability when partially blocked or damaged
L (7%): Basic correction, simplest pattern
M (15%): Recommended default
Q (25%): Suitable for adding logos
H (30%): Highest correction, most complex pattern
Data Capacity
QR codes can store up to about 3,000 characters (more for numbers only)
Numeric only: up to 7,089 digits
Alphanumeric: up to 4,296 characters
Binary: up to 2,953 bytes
Chinese characters: about 900-1,800 (varies by encoding)
Recommended Size
For physical printing, QR code size should be based on scanning distance
Scan distance 10 cm → min 2 cm × 2 cm
Scan distance 30 cm → min 3 cm × 3 cm
Scan distance 1 m → min 10 cm × 10 cm
Rule of thumb: Size ≥ Scan distance ÷ 10
Why Use QR Codes?
- Shorten user journey:Users don't need to manually type URLs — scan and arrive at the destination page, significantly reducing bounce rates
- Bridge online and offline:Physical items (posters, business cards, packaging) can link to digital content via QR codes, enabling O2O conversion
- Trackable marketing materials:Combined with UTM parameters, you can track scan traffic from each QR code and measure channel effectiveness
- Enhance user experience:WiFi connection, vCard contact features let users complete actions with one scan, reducing input errors
- Cost-effective:After printing, you can update the destination link through URL shorteners without reprinting materials
Common Use Cases
- Marketing campaign materials:Add QR codes to posters, flyers, and billboards linking to campaign pages, coupons, or registration forms
- Digital business card exchange:Generate QR codes in vCard format — recipients scan to directly save contact info, reducing input errors
- Store WiFi sharing:Customers scan to auto-connect to WiFi without asking for the password, improving service experience
- Product packaging applications:Link to product manuals, warranty registration, tutorial videos, or customer review pages
- Event check-in systems:Generate unique QR codes for each registrant — scan for quick check-in, reducing queue times
- Payments and transfers:Personal or business payment QR codes make transactions faster and more convenient
QR Code Design Specifications Reference
Choose appropriate specifications based on use case:
| Use Case | Recommended Size | Error Correction |
|---|---|---|
| Business cards | 2-3 cm | M or L |
| Flyers, DM | 3-4 cm | M |
| Posters (indoor) | 5-10 cm | M or Q |
| Posters (outdoor) | 15-30 cm | Q or H |
| With logo | Per scenario | Q or H (required) |
Size recommendations are based on normal lighting conditions with scan distance approximately 10x the QR code size. Complex environments (direct sunlight, behind glass) require larger sizes.
QR Code Design Best Practices
- Maintain sufficient contrast:Use dark foreground and light background. Avoid colors that are too similar, otherwise scanning becomes difficult
- Leave adequate quiet zone:Keep at least 4 module widths of white space around the QR code to ensure scanners can correctly identify boundaries
- Keep logo within 25%:Use high error correction (Q or H), and ensure the logo is centered to avoid covering positioning patterns
- Use URL shorteners:Shorter content means simpler QR code patterns and higher scan success rates. Use services like bit.ly
- Test on multiple devices:After creation, test scanning with iPhone, Android, and other devices to ensure all can read properly
- Verify resolution before printing:Use SVG format to avoid distortion when enlarged, or ensure PNG resolution is sufficient (at least 300 DPI)
Common QR Code Design Mistakes
- Size too small:Correct approach: Determine size based on scanning distance. Rule of thumb is QR code size should be at least 1/10 of scan distance
- Insufficient contrast:Correct approach: Use dark foreground and light background. Avoid gradients or low-contrast color combinations
- Logo too large or mispositioned:Correct approach: Logo should not exceed 25%, center it, and use Q or H error correction level
- Not testing before printing:Correct approach: Always test scanning with multiple phones before printing. Scannable on screen doesn't mean scannable when printed
- Forgetting to update after content changes:Correct approach: Use URL shorteners so printed QR codes can have their destinations updated by changing the short URL target
Related Terms
- QR Code (Quick Response Code)
- A 2D barcode format invented by Denso Wave in 1994, now an open standard used worldwide.
- UTM Parameters
- Add UTM parameters to QR code destination URLs to track scan traffic in Google Analytics.
- vCard
- Standard format for electronic business cards, storing name, phone, email, and other contact info — scan to save directly.
- Error Correction Level
- The amount of redundant data in a QR code — higher levels allow more of the code to be obscured. Available in L, M, Q, H levels.
- Quiet Zone
- The blank area around a QR code used to help scanners identify boundaries. Requires at least 4 module widths.
- Data Matrix
- Another 2D barcode format suitable for storing large amounts of data in small spaces, commonly used in industrial and medical fields.
Frequently Asked Questions
Can QR codes with logos still be scanned properly?
Yes, but you need to select a higher error correction level (Q or H recommended). Logos cover part of the QR code — high error correction allows the code to remain readable even when partially covered. Keep logo size under 25% and center it.
What's the difference between PNG and SVG formats?
PNG is a raster format, suitable for web use and screen display. SVG is a vector format that scales infinitely without quality loss, ideal for printing. Use SVG format when printing on large items.
Do QR codes expire?
QR codes themselves don't expire — they're just encoded information as a pattern. However, if the linked URL becomes invalid or the URL shortener service stops working, scanning won't lead anywhere. Use your own domain or reliable URL shortener services.
What's the difference between dynamic and static QR codes?
Static QR codes encode the destination URL directly in the pattern — once printed, it can't be changed. Dynamic QR codes encode a short URL that can be updated via the URL shortener service anytime. Dynamic QR codes usually require third-party services but allow content updates after printing.
How do I track QR code scan counts?
The simplest method is adding UTM parameters to the destination URL (use our UTM Builder), then view that UTM traffic in Google Analytics. Alternatively, use URL shortener services with tracking features (like Bitly) to see click counts and sources.
Can colored QR codes be scanned properly?
Yes, but pay attention to contrast. The foreground (dots) must be darker than the background — this is key. Avoid light foreground with dark background (inverted colors), as some scanners may not recognize it correctly. Gradient effects are unreliable; use solid colors.