Barcode Generator — Everything You Need to Know
A barcode is a machine-readable representation of data using a series of parallel lines (bars) and spaces of varying widths. Barcodes are the backbone of modern inventory management, retail checkout systems, shipping logistics, and product identification worldwide. Our free online Barcode Generator lets you create professional-grade barcodes in seconds — directly in your browser with no server uploads, no registration, and no limitations.
What Is a Barcode and How Does It Work?
Barcodes encode data into a visual pattern of black bars and white spaces that can be read by optical scanners. A barcode scanner shines a light (typically a laser or LED) across the barcode, and a photosensor detects the pattern of reflected and absorbed light. This pattern is decoded into the original data — a product number, text string, or identification code. The simplicity and reliability of this system is why barcodes have remained the standard for data capture in commerce and logistics for over 50 years.
Unlike QR codes which are two-dimensional (storing data in both horizontal and vertical patterns), traditional barcodes are one-dimensional — they encode data only in the horizontal arrangement of bars. This makes them narrower and well-suited for printing on product labels, shipping stickers, inventory tags, and retail packaging where vertical space is limited.
Barcode Types Supported by This Generator
Our barcode generator supports eight of the most widely-used barcode symbologies, each designed for specific applications and data requirements:
- Code 128 — The most versatile barcode format, supporting the full ASCII character set (letters, numbers, symbols, and control characters). Code 128 is highly compact and widely used in shipping labels, logistics, healthcare, and general-purpose identification. It automatically selects the optimal encoding subset (A, B, or C) for the shortest possible barcode.
- Code 39 — One of the oldest barcode standards, supporting uppercase letters (A–Z), digits (0–9), and a few special characters (- . $ / + % space). Code 39 is self-checking, meaning it does not require a check digit, making it popular in military (LOGMARS), automotive, and government applications.
- EAN-13 — The international standard for retail product identification used in over 100 countries. EAN-13 encodes exactly 13 digits (12 data digits + 1 check digit) and is found on virtually every consumer product sold outside North America. If you enter 12 digits, the check digit is calculated automatically.
- EAN-8 — A compact version of EAN-13 designed for products with very small packaging. It encodes 8 digits (7 data digits + 1 check digit) and is used on items like candy bars, pens, and small cosmetics where a full EAN-13 would be too large.
- UPC-A — The standard retail barcode used in the United States and Canada. UPC-A encodes 12 digits (11 data digits + 1 check digit) and is found on every product sold in North American retail stores. It is essentially equivalent to EAN-13 with a leading zero.
- ITF-14 — Used for marking cartons, cases, and pallets in shipping and logistics. ITF-14 encodes exactly 14 digits and is designed to be printed on corrugated cardboard. The "ITF" stands for Interleaved Two of Five, referring to how digits are encoded in pairs.
- MSI (Modified Plessey) — A numeric-only barcode used primarily for inventory management, warehouse shelving, and storage bin labeling. MSI barcodes are commonly found in grocery stores for shelf-edge labels and in warehouses for container tracking.
- Pharmacode — A specialized barcode used exclusively in the pharmaceutical industry for packaging control. Pharmacode encodes a single integer between 3 and 131,070 and is designed to be read even when partially printed, making it ideal for high-speed pharmaceutical packaging lines where print quality may vary.
How to Use This Barcode Generator
Creating a barcode with our tool is straightforward and takes only seconds:
- Enter your data — Type or paste the text, number, or product code you want to encode into the input field. The format depends on the barcode type you select.
- Choose barcode format — Select the appropriate barcode symbology from the dropdown menu. Each format has specific data requirements (e.g., EAN-13 requires exactly 12–13 digits, Pharmacode requires a number between 3 and 131,070).
- Generate — Click the "Generate Barcode" button. The barcode is rendered instantly as a scalable SVG image directly in your browser using the JsBarcode library. No data leaves your device.
- Download as PNG — Click "Download PNG" to save a high-resolution image of your barcode. The SVG is converted to a canvas element and exported as a PNG file suitable for printing at any size.
Common Use Cases for Barcodes
Barcodes are used across virtually every industry. Here are the most common applications our users generate barcodes for:
- Retail products — EAN-13, EAN-8, and UPC-A barcodes are required on all retail products for point-of-sale scanning. If you're launching a product, you'll need one of these formats.
- Shipping and logistics — Code 128 and ITF-14 are standard for shipping labels, carton marking, and supply chain tracking. They encode tracking numbers, SKUs, and routing information.
- Inventory management — MSI and Code 39 barcodes are used on warehouse shelves, storage bins, and asset tags to enable quick scanning during stock counts and picking operations.
- Healthcare — Code 128 barcodes are used on patient wristbands, medication labels, and laboratory samples for accurate identification and safety tracking.
- Library systems — Code 39 is commonly used for library book labels and patron cards due to its simplicity and self-checking nature.
- Event tickets — Code 128 barcodes on tickets and boarding passes enable fast, reliable scanning at entry points and gates.
Tips for Creating High-Quality Barcodes
- Always verify your barcode data matches the format requirements (correct number of digits, valid characters, etc.) before printing.
- Print at a minimum resolution of 300 DPI to ensure scanner readability.
- Maintain adequate quiet zones (white space) on both sides of the barcode — at least 10× the narrowest bar width.
- Use high-contrast printing: black bars on white background produces the most reliable scans.
- Test scan your barcode with multiple devices before mass-printing to confirm readability.
- For retail products, obtain a valid GS1 company prefix before generating EAN or UPC barcodes to ensure global uniqueness.
Frequently Asked Questions
What barcode format should I use for my product?
For retail products sold in North America, use UPC-A (12 digits). For products sold internationally, use EAN-13 (13 digits). For small packages, EAN-8 works well. For shipping cartons and cases, use ITF-14. For general-purpose labeling with text and numbers, Code 128 is the most versatile choice. You'll need a GS1 company prefix to obtain valid product numbers for retail use.
Is there a character limit for barcodes?
Each format has different limits. Code 128 can encode any number of ASCII characters (though longer data means wider barcodes). Code 39 supports uppercase letters, digits, and a few symbols. EAN-13, EAN-8, UPC-A, and ITF-14 are fixed-length numeric formats. MSI supports digits only with no fixed length. Pharmacode encodes a single number from 3 to 131,070. The input hint below the text field updates based on your selected format.
Can I use these barcodes commercially?
Yes. The barcodes generated by this tool are standard-compliant and suitable for commercial use. However, for retail product barcodes (EAN-13, UPC-A), you must obtain a valid GS1 company prefix and assigned product numbers. You cannot simply generate random numbers for retail products — they must be globally unique identifiers registered through GS1. For internal inventory or labeling purposes, you can use any valid data.
Why is my barcode not generating?
The most common reason is invalid data for the selected format. EAN-13 requires exactly 12 or 13 digits, EAN-8 requires 7 or 8 digits, UPC-A requires 11 or 12 digits, ITF-14 requires 14 digits, MSI requires digits only, and Pharmacode requires a number between 3 and 131,070. Code 39 only supports uppercase letters, digits, and limited symbols. Check that your input matches the format requirements shown in the hint text.
Is my data private when generating barcodes?
Absolutely. The barcode is generated entirely in your browser using the JsBarcode JavaScript library. Your data never leaves your device — no server requests are made, nothing is stored or logged. The generation process is 100% client-side, ensuring complete privacy and security of your data.