Barcode Generator

What is the difference between EAN-13, UPC-A, and Code 128?

Different symbologies for different purposes. EAN-13 (European Article Number, 13 digits) is the global retail standard for consumer products, used in supermarket checkouts worldwide. UPC-A (Universal Product Code, 12 digits) is the older North American equivalent; UPC-A codes are valid EAN-13 with a leading zero. Both are numeric-only and require GS1-assigned prefixes for commercial use. Code 128 is a general-purpose alphanumeric barcode for internal logistics, asset tracking, and industrial applications where you control both ends of the supply chain and do not need GS1 registration. Choose retail symbologies for retail, Code 128 for internal use.

Do I need to register with GS1 to use EAN codes?

For commercial retail use, yes. Real retailers (Walmart, Amazon, Target, supermarkets) scan barcodes against the GS1 GTIN registry and will reject or flag products with codes not assigned through GS1's prefix allocation. The GS1 registration fee varies by country and volume (roughly US$250/year for a small company in the US, with tiered fees for larger prefix blocks). For internal use, demo/testing, or closed-loop applications where you control the scanners, you can generate and use any valid-format EAN code freely — but those codes will collide with real products and must not be sold through general retail channels.

Which QR error-correction level should I choose?

Depends on your physical context and data size. L (7% recovery) is for digital-only use (displayed on screens, fresh prints on clean paper) where no damage is expected; produces the smallest code for a given payload. M (15%) is the common default for print — handles minor smudges, scratches, and ink spread gracefully. Q (25%) for outdoor or high-wear contexts like event badges, stickers that may be partially covered, or anywhere dust/water exposure is likely. H (30%) specifically when you want to overlay a logo in the center — the QR can lose up to 30% of its modules and still decode, so the logo displaces error-correction bits not data bits. Larger correction means larger codes; pick the lowest that serves your reliability needs.

Can I embed a URL in a Code 128 or only in a QR code?

Technically Code 128 can encode any ASCII text including URLs, but it would produce an extremely wide 1D barcode (roughly 30mm per 5 characters of Code 128C or 20mm per 5 characters of Code 128B). A 50-character URL would be 200+mm wide, far too long for practical label application. Use Code 128 for short alphanumeric identifiers (5–20 characters) like serial numbers or internal asset tags. Use QR for URLs, WiFi credentials, vCards, or any payload longer than about 20 characters where you want a compact 2D code. 1D barcodes are for short identifiers; 2D codes are for data payloads.

Why do some of my printed barcodes fail to scan?

Print quality is the usual culprit. Common failure modes: inkjet printers bleed ink which merges thin bars (EAN-13 bars at small sizes can fuse together and lose the digit encoding); toner banding on a dying laser cartridge introduces gaps inside what should be solid bars; glossy paper produces glare that blinds the scanner laser; scaling a barcode in your page-layout tool with non-proportional scaling distorts the bar widths so the decoder sees invalid ratios; excessive compression when embedding the barcode as an image introduces JPEG artifacts that destroy the sharp edges. For production use: laser print at 600 DPI on matte label stock, keep barcodes as SVG or high-resolution PNG (no JPEG), and never scale non-proportionally.