Barcode Generator
Generate Code128 and Code39 barcodes from any text or number. Download as PNG for printing or digital use.
How to Use the Barcode Generator
- Enter data -- Type the text or numbers you want to encode in the barcode.
- Choose format -- Select Code 128 (supports all ASCII) or Code 39 (uppercase, digits, and some symbols).
- Select height -- Pick Small, Medium, or Large barcode height.
- Generate -- Click the button to render the barcode on screen.
- Download -- Click "Download PNG" to save the barcode as an image file.
About Barcodes
Barcodes are machine-readable representations of data using patterns of parallel lines of varying widths. They were first patented in 1952 and have become ubiquitous in retail, logistics, healthcare, and manufacturing. Linear (1D) barcodes like Code 128 and Code 39 encode data in a single row of bars.
Code 128 is a high-density symbology that can represent all 128 ASCII characters, making it versatile for shipping labels, inventory management, and product identification. Code 39 is an older but widely supported format that encodes uppercase letters, digits, and a handful of special characters. This tool generates barcodes entirely in your browser using the HTML5 Canvas API -- no server processing required.
Use Cases for Barcodes
Linear barcodes remain essential across countless industries despite the rise of QR codes. Here are the most common applications for Code 128 and Code 39 barcodes.
Shipping and Logistics
Code 128 is the standard barcode format for shipping labels, tracking numbers, and logistics barcodes worldwide. Carriers like FedEx, UPS, and DHL use Code 128 for package tracking because of its high density and support for the full ASCII character set, allowing alphanumeric tracking codes to be encoded compactly.
Inventory and Asset Management
Warehouses, libraries, and IT departments use barcodes to track physical items. Each item receives a unique barcode label that can be scanned during check-in, check-out, and auditing. Code 128 is preferred for its compact size, while Code 39 is still used in legacy systems.
Document and File Tracking
Law firms, hospitals, and government agencies use barcodes on documents and file folders for rapid retrieval and chain-of-custody tracking. Scanning a barcode is faster and more accurate than manual data entry, reducing filing errors and improving workflow efficiency.
Manufacturing and Production
Barcodes on work orders, parts bins, and assembly stations enable real-time production tracking. Workers scan barcodes to record progress through manufacturing stages, supporting lean manufacturing and quality control processes.
Event Badges and ID Cards
Conferences, trade shows, and corporate events use barcodes on attendee badges for session check-in, lead scanning, and access control. Code 128 barcodes are compact enough to fit on standard badge inserts while encoding attendee IDs reliably.
Barcode Type Comparison
Different barcode symbologies serve different needs. This table compares the two formats supported by this tool with other common barcode types for reference.
| Barcode Type | Characters | Density | Common Use |
|---|---|---|---|
| Code 128 | Full ASCII (128 chars) | High | Shipping, logistics, inventory |
| Code 39 | A-Z, 0-9, symbols (43 chars) | Low | Government, defense, manufacturing |
| EAN-13 | Numeric only (13 digits) | Medium | International retail products |
| UPC-A | Numeric only (12 digits) | Medium | North American retail products |
| ITF-14 | Numeric only (14 digits) | Medium | Carton and pallet labeling |
For most general-purpose applications, Code 128 is the best choice due to its support for the full ASCII character set and compact encoding. Code 39 is useful when compatibility with older scanning equipment is required, particularly in government and defense contexts where it has been the standard for decades.
Printing and Scanning Best Practices
The quality of a printed barcode directly affects its scannability. Use a laser printer with at least 300 DPI resolution for clear, crisp bars. Inkjet printers can produce scannable barcodes, but ink bleeding may reduce reliability, especially at smaller sizes. Always print in black on a white background for maximum contrast.
Ensure adequate quiet zones -- the blank white space on both sides of the barcode. The quiet zone should be at least 10 times the width of the narrowest bar, or a minimum of 6 mm (0.25 inches). Without sufficient quiet zones, scanners may fail to locate the start and stop patterns of the barcode.
For reliable scanning, the barcode height should be at least 15% of the total barcode width, or a minimum of 15 mm (0.6 inches) for handheld scanners. Taller barcodes are easier to scan because they give the laser more surface area to read. Use the "Large" height option when generating barcodes intended for print.
Frequently Asked Questions
Code 128 is a high-density linear barcode symbology that can encode all 128 ASCII characters. It is widely used in shipping, packaging, and supply chain management due to its compact size and high reliability.
Code 39 is one of the earliest barcode symbologies, supporting uppercase letters A-Z, digits 0-9, and special characters (-.$/+% and space). It is commonly used in government and manufacturing applications.
Yes. Click the "Download PNG" button to save the generated barcode as a PNG image. The image includes the barcode and the text label beneath it.
Code 128 can encode all 128 ASCII characters and produces more compact barcodes, making it ideal for shipping labels and modern applications. Code 39 only supports uppercase letters, digits, and a few symbols, but is widely supported by older scanners and is the standard in government and defense applications.
For internal use such as inventory tracking and asset management, yes. For retail products sold in stores, you need a GS1-registered UPC or EAN barcode with a valid manufacturer prefix purchased from GS1. This tool generates Code 128 and Code 39 barcodes intended for general-purpose use.
Use a laser printer at 300 DPI or higher for clear, crisp bars. Ensure the barcode has sufficient quiet zones (white space) on both sides -- at least 6 mm. The barcode should be at least 15 mm tall for reliable handheld scanning. Use the Large height option when generating barcodes intended for print.
Code 128 can encode all 128 ASCII characters, including uppercase and lowercase letters, digits 0-9, symbols, and even control characters. This makes it one of the most versatile linear barcode formats available, suitable for virtually any alphanumeric data.