Generate barcodes online in common inventory and label formats.
TempGBox
Barcode Generator
Generate barcodes in various formats: CODE128, CODE39, EAN13, EAN8, UPC, and more. Download as PNG image.
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Format: CODE128
💡 Format Requirements:
What is Barcode Generator?
Barcode Generator helps with Barcode Generator Online. Generate barcodes in various formats: CODE128, CODE39, EAN13, EAN8, UPC, and more. Download as PNG image.
TempGBox keeps the workflow simple in your browser, so you can move from input to result quickly without extra software.
How to use Barcode Generator
- Open Barcode Generator and enter the text, value, file, or settings you want to work with.
- Review the output and adjust the available options until the result matches your use case.
- Copy, download, or reuse the final result in your workflow, content, app, or support task.
Why use TempGBox Barcode Generator?
- Generate barcodes in various formats: CODE128, CODE39, EAN13, EAN8, UPC, and more. Download as PNG image
- Useful for Barcode Generator Online
- Fast browser-based workflow with no signup required
Common uses for Barcode Generator
Barcode Generator is useful for Barcode Generator Online. It fits well into quick checks, repeated office work, development flows, content updates, and everyday browser-based problem solving.
Because the tool is available instantly on TempGBox, you can handle one-off tasks and repeated workflows without installing extra software.
FAQ
Is Barcode Generator free to use?
Yes. Barcode Generator on TempGBox is free to use and does not require signup before you start.
What is Barcode Generator useful for?
Barcode Generator is especially useful for Barcode Generator Online.
Understanding Barcode Generator
Linear barcodes encode data in the widths and spacings of parallel lines. Code 128 is the most versatile 1D symbology — it supports all 128 ASCII characters, uses variable-length encoding, and automatically selects between three character sets (A for control characters, B for mixed-case alphanumeric, C for digit pairs) to minimize barcode width. A Code 128 barcode for "ABC123" is physically shorter than the same data in Code 39 because Code 128's denser encoding packs more information per unit width. This makes Code 128 the default choice for shipping labels, inventory, and general-purpose identification.
EAN-13 and UPC-A are fixed-length numeric-only symbologies governed by GS1 (Global Standards One). UPC-A encodes exactly 12 digits and is used primarily in North American retail. EAN-13 encodes 13 digits and is the international standard — a UPC-A barcode is technically an EAN-13 with a leading zero. Both include a check digit calculated using the Luhn-variant modulo-10 algorithm: odd-positioned digits are summed, even-positioned digits are summed and multiplied by 3, and the check digit brings the total to the nearest multiple of 10. This single digit catches all single-digit errors and most transposition errors.
Print quality directly determines scan reliability. The key metric is the X-dimension — the width of the narrowest bar element. GS1 General Specifications require a minimum X-dimension of 0.264mm (10.4 mil) for retail POS scanning of EAN/UPC barcodes. For thermal label printers, this translates to a minimum print resolution of 203 DPI, though 300 DPI is recommended for dense symbologies like Code 128 or QR codes. The quiet zone (blank margin on each side) must be at least 10X for EAN-13 and 10X for Code 128. Truncating the quiet zone is the most common cause of scan failures in production environments.
GS1 Application Identifiers (AIs) extend barcode content beyond simple product identification. AI (01) encodes the Global Trade Item Number (GTIN), AI (10) encodes a batch/lot number, AI (17) encodes an expiration date in YYMMDD format, and AI (21) encodes a serial number. These AIs are typically encoded in GS1-128 barcodes (Code 128 with a special FNC1 start character) and enable supply chain traceability from manufacturer to consumer. The GS1 Digital Link standard now maps these same identifiers to URLs, bridging physical barcodes and web-based product information.
Step-by-Step Guide
- Choose the barcode symbology based on your use case: Code 128 for general alphanumeric data, EAN-13 for international retail products, UPC-A for North American retail, Code 39 for legacy industrial systems, or ITF-14 for outer cartons and shipping containers.
- Enter the data to encode. For EAN-13, enter exactly 12 digits (the 13th check digit is calculated automatically). For UPC-A, enter 11 digits. For Code 128, enter any ASCII text — the encoder will automatically select the optimal character set to minimize barcode width.
- Verify the check digit if applicable. The tool calculates and appends the correct check digit for EAN-13, UPC-A, and other symbologies that require it. Compare the generated check digit against any existing documentation to confirm the data is correct.
- Set the output dimensions. For print applications, ensure the X-dimension meets GS1 minimums (0.264mm for retail POS). Specify the height — GS1 recommends at least 69% of the barcode width for EAN-13 to maintain scannability from multiple angles.
- Configure display options: whether to show the human-readable text below the bars, the font size for that text, and the quiet zone margin. The human-readable interpretation (HRI) must be present on retail packaging as a fallback when the barcode is unscannable.
- Download the generated barcode as a PNG or SVG. SVG is preferred for print workflows because it scales to any resolution without pixelation. PNG is suitable for screen display and web applications where vector support is not needed.
- Test the barcode with a physical scanner or a smartphone scanner app before mass production. Verify that the correct data decodes and that the symbology is recognized. Print a test sheet at your target DPI and scan from the expected distance.
Real-World Use Cases
A small business registering products on Amazon needs UPC-A barcodes for their SKUs. They purchased a GS1 Company Prefix and need to generate valid barcodes with correct check digits for each product variation. The tool generates print-ready SVGs that meet Amazon's barcode requirements.
A warehouse manager is implementing a bin location system using Code 128 barcodes. Each shelf position gets a barcode like "A-03-12" (aisle A, rack 3, shelf 12) printed on adhesive labels at 300 DPI. Workers scan locations with handheld terminals to log inventory movements.
A pharmaceutical company needs to generate GS1-128 barcodes encoding GTIN, batch number, and expiration date for each drug lot. The concatenated AI string (01)04012345678901(10)BATCH42(17)261231 is encoded into a single barcode that carries full traceability information.
A race organizer prints EAN-13 barcodes on runner bibs for timing chip activation. Each bib gets a unique barcode generated from the runner's registration number, and the timing system scans them at the start line to link the physical chip ID to the registered participant.
An inventory clerk needs to label 200 assets with unique identifiers for an annual audit. They generate a batch of Code 128 barcodes from a CSV of asset numbers, print them on a label printer, and affix them to equipment for handheld scanner identification.
Expert Tips
When generating Code 128 barcodes for numeric-only data, ensure the encoder uses character set C, which encodes digit pairs and produces a barcode nearly half the width of set B. Good encoders switch automatically, but some naive implementations default to set B for all input.
For label printing, always generate barcodes as SVG rather than PNG. Raster images at 72 DPI look fine on screen but produce blurry bars when printed. SVG renders at the printer's native resolution (300–600 DPI), producing crisp edges that scan reliably.
Test barcode readability at the worst-case angle and distance your scanner will encounter. A barcode that scans perfectly at 6 inches perpendicular to the scanner may fail at 12 inches or at a 30-degree tilt. GS1 verification grades (A through F) quantify this tolerance.
Frequently Asked Questions
What is the difference between Code 128, EAN-13, and UPC-A?
Code 128 is a variable-length symbology that encodes the full ASCII character set and is used for shipping, inventory, and general identification. EAN-13 is a fixed-length 13-digit numeric symbology used internationally for retail products. UPC-A is a 12-digit subset of EAN-13 used primarily in North American retail. EAN-13 and UPC-A require a GS1 Company Prefix for legitimate retail use.
How is the check digit calculated for EAN-13?
The check digit uses a weighted modulo-10 algorithm. Starting from the left, digits in odd positions are multiplied by 1 and digits in even positions are multiplied by 3. The products are summed, and the check digit is the number needed to bring the total to the nearest multiple of 10. For example, if the sum is 57, the check digit is 3 (because 60 - 57 = 3).
What DPI should I use for printing barcodes?
A minimum of 203 DPI is required for standard retail barcodes, but 300 DPI is recommended for consistent scan reliability, especially with dense symbologies like Code 128 or when printing small barcodes. For high-density 2D symbologies (QR, DataMatrix), 300–600 DPI ensures the smallest modules are cleanly resolved by the print head.
Why does my barcode fail to scan?
The most common causes are: insufficient quiet zone (blank margin) around the barcode, printing at too low a resolution causing bars to bleed together, incorrect contrast (bars must be dark on a light background), and physical damage or wrinkling of the printed label. Verify the quiet zone is at least 10 times the narrowest bar width on each side.
Do I need a GS1 license to use barcodes?
For internal use (warehouse bins, asset labels, internal documents), no license is required — you can generate Code 128 or Code 39 barcodes with any data you choose. For retail products sold in stores or online marketplaces, you need a GS1 Company Prefix to generate legitimate EAN-13 or UPC-A barcodes. GS1 membership starts at around $250/year in the US.
Privacy: Barcode generation is performed entirely in your browser using client-side JavaScript. The data you encode — product numbers, serial numbers, text strings — is never transmitted to any server or stored beyond your browser session.