1D vs 2D Barcodes: What's the Difference?
Barcodes fall into two broad families:
- 1D (one-dimensional) barcodes encode data in a series of parallel vertical bars and spaces. They can only be read horizontally, and they hold a limited amount of data — typically 10–50 characters. Examples: Code 128, EAN-13, UPC-A, Code 39, ITF-14.
- 2D (two-dimensional) barcodes encode data in a grid of squares or dots. They can be read in any direction and hold far more data — hundreds to thousands of characters. Examples: QR Code, Data Matrix, PDF417.
For most retail and warehouse use cases, a 1D barcode is all you need. 2D barcodes become useful when you need to pack more information into a small label, or when customers will scan the code with a smartphone.
The 7 Most Common Barcode Types
Code 128
The workhorse of warehouse and inventory labeling. Encodes all 128 ASCII characters with high data density. No inherent length limit.
Generate Code 128 →EAN-13
The international retail standard. 13 digits, used on virtually every product sold outside North America. Required by most global retailers and GS1.
Generate EAN-13 →UPC-A
The North American retail standard. 12 digits, required for products sold in US and Canadian supermarkets, big-box stores, and Amazon FBA.
Generate UPC-A →Code 39
An older, simpler format used in automotive, aerospace, and government applications. Encodes letters and numbers. Self-checking — no check digit required.
Generate Code 39 →ITF-14
Used on outer shipping cartons (cases and pallets). Encodes 14 digits including a GS1 prefix. Printed directly on corrugated cardboard — no label needed.
Learn about ITF-14 →QR Code
The most recognizable 2D barcode. Stores URLs, contact info, plain text, or Wi-Fi credentials. Scannable with any smartphone camera — no dedicated scanner needed.
Generate QR Code →Data Matrix
A compact 2D format used in pharma, electronics, and small-part manufacturing. Can encode a lot of data in a tiny footprint — as small as 1mm × 1mm.
Generate Data Matrix →Quick Reference: Which Barcode Type Should You Use?
| Use Case | Recommended Format | Why |
|---|---|---|
| Selling in US / Amazon FBA | UPC-A | Required by US retailers and Amazon for most product categories |
| Selling internationally / EU | EAN-13 | Global standard; also accepted in the US (UPC-A is a subset of EAN-13) |
| Internal inventory / SKU labels | Code 128 | Most compact 1D format; encodes any alphanumeric SKU |
| Clothing & garment tags | Code 128 or EAN-13 | Code 128 for internal; EAN-13 if selling through retail channels |
| Shipping cartons / pallets | ITF-14 | GS1 standard for case-level barcoding; printable on corrugated stock |
| QR menus / URLs / contactless | QR Code | Customer-facing; smartphone-scannable without a dedicated reader |
| Pharma, electronics, small parts | Data Matrix | High data density in minimal space; used in GS1 healthcare standards |
| Automotive / government / DoD | Code 39 | Legacy standard in these industries; simple and self-checking |
How Do Barcodes Work?
Every barcode encodes data as a pattern that a scanner can read optically. In a 1D barcode, the widths of the bars and the spaces between them represent digits or characters. A laser scanner bounces light off the barcode and measures how much is reflected — dark bars absorb light, white spaces reflect it — producing a digital signal that a decoder converts back to text or numbers.
2D barcodes work on the same optical principle but encode data in a two-dimensional matrix. An image sensor (camera) captures the entire pattern at once rather than scanning a single line. This is why your phone camera can read a QR code while it typically can't read a shelf barcode without a dedicated app.
Do I Need to Buy a Barcode?
For internal use (your own warehouse, inventory, or internal SKU tracking), you can generate any barcode you like — no purchase or registration required. The barcode is just a machine-readable label for your data.
For retail sale through major retailers or marketplaces like Amazon, Walmart, or Target, you typically need a GS1-registered UPC or EAN. GS1 is the nonprofit that manages the global barcode numbering system. You purchase a company prefix from GS1, which guarantees your product numbers are globally unique.
Amazon, for its part, accepts GS1-issued GTINs (Global Trade Item Numbers) or brand-registered ASINs. Using a recycled or "grey-market" UPC can get your listing suppressed.
Ready to generate barcodes? Our free bulk barcode generator supports all 7 formats above. Paste your SKUs or product list, pick a format, and download print-ready PDF labels — no signup required.
Generate Barcodes Free →Choosing Between Code 128, EAN-13, and UPC-A
These three are the most commonly confused. Here's a quick distinction:
- UPC-A is 12 digits, North America only (though globally accepted). It's a subset of EAN-13 — an EAN-13 with a leading zero is the same as a UPC-A.
- EAN-13 is 13 digits, the global standard. If you're selling in Europe, Australia, Asia, or anywhere outside the US, use EAN-13.
- Code 128 encodes any characters (not just numbers) and has no fixed length — making it ideal for SKUs like "SKU-2024-BLK-M" that mix letters and numbers.
If you're unsure, Code 128 for internal use, EAN-13 for retail is a safe default for most small businesses operating internationally.
What About QR Codes?
QR codes are excellent for customer-facing applications — linking to a product page, a how-to video, a Wi-Fi password, or a loyalty program sign-up. They're free to generate and require no registration.
They are not a substitute for retail barcodes. A supermarket's point-of-sale system expects a laser-scannable 1D barcode at the checkout, not a QR code. Use QR codes alongside — not instead of — your retail barcode.
Quiet Zones and Print Quality
Every barcode format requires a blank margin on both sides called a quiet zone. Without it, a scanner may fail to detect the start or end of the code and produce a misread. Our generator adds the correct quiet zone automatically for every format.
Print at a minimum of 203 DPI for laser/inkjet labels. For thermal printers, use a resolution of 300 DPI or higher for reliable scanning. Avoid printing barcodes on textured or glossy paper without a matte laminate, as reflected glare can cause misreads.