Barcode & QR Code Symbology Guide
Complete technical reference for 50+ barcode and 2D code standards — covering character sets, data capacity, check digits, ISO standards, and real-world applications.
1D Linear Codes — Part 1
The original barcode family. Linear (1D) barcodes encode data in the width and spacing of parallel vertical bars. They are scanned by laser or CCD scanners and remain the most widely deployed symbology type worldwide.
| Name | Standard | Character Set | Capacity | Check Digit | Applications | Generator |
|---|---|---|---|---|---|---|
| Code 128 | ISO 15417 | Full ASCII (128 chars), GS1 Application Identifiers | Up to ~48 chars (practical); limited by size | YES | Shipping labels, GS1-128 logistics, healthcare, retail, HIBC | Generate |
| GS1-128 (EAN-128 / UCC-128) | GS1 General Specifications | Full ASCII with GS1 Application Identifiers (AI) | Up to 48 chars | YES | Supply chain, shipping, SSCC, GTIN-14, lot/batch tracking, food safety | Generate |
| Code 39 | ANSI/AIM BC1, ISO 16388 | 43 characters: A–Z, 0–9, space, - . $ / + % | Variable; typically up to 20–25 chars for readability | NO | US DoD (LOGMARS), automotive, healthcare, inventory | Generate |
| Code 39 Extended (Full ASCII) | AIM USS-39 | Full ASCII (128 chars) via encoding pairs | Variable | NO | LOGMARS, assets, broader character set requirements | Generate |
| Code 93 | AIM USS-93 | Full ASCII (128 chars) | Variable (denser than Code 39) | YES | Canada Post, logistics, complement to Code 39 in higher-density needs | Generate |
| EAN-13 | ISO 15420, GS1 | Numeric only (0–9) | 12 data digits + 1 check digit = 13 digits | YES | Retail product identification worldwide (books, food, consumer goods) | Generate |
| EAN-8 | ISO 15420, GS1 | Numeric only (0–9) | 7 data digits + 1 check digit = 8 digits | YES | Small product retail packaging where EAN-13 won't fit | Generate |
| UPC-A | GS1 General Specifications | Numeric only (0–9) | 11 data digits + 1 check digit = 12 digits | YES | Retail products in USA and Canada (subset of EAN-13) | Generate |
| UPC-E | GS1 General Specifications | Numeric only (0–9) | 6 data digits (zero-suppressed from UPC-A) | YES | Small packages in North America; compressed version of UPC-A | Generate |
| EAN-13 + 2 / + 5 Add-onAppended after the main EAN/UPC symbol | ISO 15420 Supplement | Numeric only | 2 or 5 supplemental digits | NO | Magazines (issue number), books (price), pharmaceuticals (weight) | Generate |
| ITF-14 (Interleaved 2/5) | ISO 16390, GS1 | Numeric only (0–9, even digit count) | 14 digits (GTIN-14) | YES | Outer cases, cartons, logistics — non-POS scanning | Generate |
| Interleaved 2 of 5 (ITF) | ISO 16390 | Numeric only (0–9, even digit count) | Variable (pairs of digits) | NO | Warehouse, distribution, industrial | Generate |
| Standard 2 of 5 (Industrial 2 of 5) | AIM USS-2/5 | Numeric only (0–9) | Variable | NO | Airline baggage (old standard), industrial, photo development | Generate |
| IATA 2 of 5 | IATA | Numeric only (0–9) | Variable | NO | Airline industry baggage and cargo tracking (legacy) | Generate |
| Code 11 (USD-8) | Intermec | 0–9 and dash (−) | Variable | YES | Telecommunications equipment labelling | Generate |
What is a barcode?
A barcode is a machine-readable visual representation of data. 1D (linear) codes encode data in the width of vertical bars; 2D codes encode data in a two-dimensional grid of modules, allowing far more data in a smaller area.
Which barcode should I use?
Retail products: EAN-13 or UPC-A. QR/URL/mobile: QR Code. Shipping: Code 128 or GS1-128. Medical devices: GS1 Data Matrix.
Standards bodies
- GS1— Retail, logistics, healthcare
- ISO / IEC— International standards
- AIM Global— Industry barcodes
- USPS / Royal Mail— Postal codes
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