일반 텍스트 QR Code: 시리얼 번호, 메시지, 원시 데이터
When and how to use plain text QR codes: serial numbers, internal identifiers, messages, and raw data encoding strategies.
Plain Text QR Codes: Serial Numbers, Messages, and Raw Data
Plain text QR codes encode raw strings without any URI scheme or structured format. The scanner displays the text directly — no browser, app, or action is triggered automatically.
When to Use Plain Text
Unlike URL, WiFi, or vCard QR codes that trigger specific device actions, plain text QR codes simply display their content. This is appropriate for:
- Serial numbers and identifiers: Product tracking, asset management
- Short messages: Greeting cards, scavenger hunts, art installations
- Verification codes: Two-factor backup codes, licence keys
- Internal data: Warehouse locations, batch numbers, equipment IDs
- Encoded payloads: JSON, XML, or custom data for specific applications
Encoding Considerations
Plain text uses Byte mode encoding (8 bits per character). For text containing only digits, Numeric mode is much more efficient (3.3 bits per digit). Most QR code libraries automatically select the optimal encoding mode.
Size and Capacity
| Text Length | Approximate Version (EC-M) |
|---|---|
| 10 chars | Version 1 (21x21) |
| 50 chars | Version 3 (29x29) |
| 100 chars | Version 5 (37x37) |
| 500 chars | Version 12 (65x65) |
| 1,000 chars | Version 18 (89x89) |
For long text, consider linking to a web page via URL QR code instead of encoding the full text.
Character Encoding
By default, QR codes use modo byte (Latin-1, 256 caracteres)." data-category="Standards & Specifications">ISO 8859-1 for Byte mode. For characters outside this set (CJK, emoji, accented characters), use ECI mode to specify UTF-8 encoding. Not all scanners handle ECI correctly, so test with special characters.
Industrial Applications
Plain text QR codes are widely used in manufacturing and logistics:
- Part identification: Encode part numbers, lot codes, and revision numbers
- Work-in-progress tracking: Scan at each station to update status
- Inventory management: Location codes (e.g., "A3-R2-S5" for aisle-rack-shelf)
- Quality control: Inspection codes and pass/fail identifiers
Best Practices
- Keep text concise — long strings create large, hard-to-scan codes
- Use Numeric mode when possible (digits only)
- For structured data, consider JSON-in-QR with a compact schema
- Test character encoding on multiple scanner applications
- Provide context near the QR code explaining what the text represents
Key Takeaways
- Plain text QR codes display raw content without triggering device actions
- Ideal for serial numbers, identifiers, messages, and internal data
- Byte mode handles any character; Numeric mode is more efficient for digits
- Character encoding (ISO 8859-1 vs UTF-8) affects scanner compatibility
- Keep text short or use a URL QR code linking to longer content