Barcode Analyzer
Analyze barcode numbers, validate check digits, and learn about barcode structure. Decode EAN-13, UPC, Code 39 formats.
About Barcodes
Barcodes encode data in patterns of parallel lines (bars) with varying widths and spacings. They're used worldwide for product identification, inventory tracking, and data encoding.
Common Barcode Types
EAN-13
The most common retail barcode worldwide. 13 digits encoding country of origin, manufacturer, product, and a check digit.
UPC-A
12-digit barcode used primarily in North America. Similar structure to EAN-13 but with different country prefixes.
Code 39
Variable-length alphanumeric barcode. Can encode letters A-Z, digits 0-9, and special characters. Often used in logistics and identification.
Barcodes in Geocaching
Barcodes appear in geocaching puzzles in various ways:
- Hidden coordinates: Numbers encoding lat/long
- Product lookup: Real products with puzzle relevance
- Check digit puzzles: Using validation algorithms
- Binary patterns: Bar widths encoding data
Check Digit Calculation
Barcodes use check digits to detect scanning errors. For EAN-13:
- Multiply odd-position digits by 1, even-position by 3
- Sum all products
- Check digit = (10 - sum mod 10) mod 10