How to Create Barcodes Online — Free Generator for Labels and Products

There are dozens of barcode generators online, and most of them work fine for the actual generation part. The problem is never the tool — it's the decisions you make before clicking "Generate." Which format? How many digits? What's a check digit? Do I need to register the number? Can I just make one up?

This guide covers the practical side of creating barcodes: picking the right format, avoiding common mistakes, and getting a file that actually scans when printed on a label. The Barcode Generator handles five standard formats and exports to both SVG and PNG — all in the browser, no uploads required.

Picking the Right Format

There are five barcode symbologies available, and each one exists for a specific reason. Using the wrong format won't break anything technically — the barcode will still be valid — but it might not match what a scanner or system expects.

Code 128 is the default choice when you're not sure. It encodes letters, numbers, and symbols with variable length. Shipping labels, asset tags, internal tracking codes, event tickets, employee badges — if the barcode isn't going on a retail product, Code 128 is almost certainly what you want.

EAN-13 is the standard for retail products sold internationally. Exactly 13 digits. The first 2–3 digits identify the country of the issuing GS1 office (not where the product was made), the next block identifies the company, the next identifies the specific product, and the last digit is a check digit. Every product you've scanned at a European or Asian checkout used EAN-13.

UPC-A is the North American retail standard. 12 digits. Functionally identical to EAN-13 — a UPC-A code is just an EAN-13 with a leading zero. If your product only sells in the US or Canada, UPC-A is the conventional choice. If it sells internationally, use EAN-13.

Code 39 encodes uppercase letters, digits, and a handful of special characters. It's the legacy standard in automotive (VIN labels), military (CAGE codes), and some healthcare systems (HIBC). If the system you're integrating with specifically asks for Code 39, use it. Otherwise, Code 128 does everything Code 39 does, but more compactly.

ITF-14 is for outer shipping cartons — the box that contains individual products. Exactly 14 digits. You'll see these on the brown shipping boxes in warehouses, not on the products inside them. The number typically matches the product's GTIN with a packaging indicator digit prepended.

The Check Digit Problem

EAN-13, UPC-A, and ITF-14 all require a check digit — the last digit of the number, calculated from the preceding digits using a modulo-10 algorithm. The check digit isn't arbitrary. If you enter a random 13-digit number for an EAN-13 barcode, there's a 90% chance the last digit is wrong and the generator will reject it.

Here's how it works for EAN-13. Take the first 12 digits. Multiply each digit by either 1 or 3, alternating. Sum the results. The check digit is whatever you need to add to make that sum a multiple of 10. If the sum is 57, the check digit is 3 (because 57 + 3 = 60).

You don't need to calculate this by hand — online check digit calculators exist, and GS1 provides one on their website. But you do need to know it exists, because "I typed in my number and the barcode generator says it's invalid" is the most common issue people run into. Code 128 and Code 39 don't have this problem — they accept whatever you type.

Creating vs. Registering a Barcode

This is the most misunderstood part of the process. Generating a barcode image and registering a barcode number are two completely separate things.

Generating means rendering a number as a visual barcode image. Any tool can do this, including the Barcode Generator. You type a number, it draws the bars, you download the file. No restrictions, no registration, no cost.

Registering means getting a legitimate product number from GS1 (the global barcode standards organization). This costs money — GS1 membership fees vary by country and company size. Registration gives you a unique company prefix, and you assign product numbers under that prefix. Without registration, your barcode number might collide with someone else's product.

When you need to register: selling through retail stores, marketplaces (Amazon, Walmart), or any channel where scanners match barcodes to a product database. When you don't: internal inventory, asset tracking, personal cataloging, prototyping, events, or any system where you control both the barcode and the database.

SVG vs. PNG — Getting the Right File

The generator outputs two formats. Which one you need depends on what happens next.

SVG for print. SVG is a vector format — it describes the barcode as mathematical shapes, not pixels. It scales to any size without quality loss. A barcode downloaded at screen resolution prints perfectly on a 300 DPI label printer, a 600 DPI laser printer, or a commercial press. If the barcode will be printed — on a label, packaging, shipping document, or anything physical — download SVG.

PNG for screens. PNG is a raster format — fixed pixels. It's the right choice for embedding in emails, websites, presentations, or digital documents. The resolution depends on the scale setting you chose in the generator. For most screen uses, 2x or 3x scale is sufficient. If you need to check whether a PNG image has enough resolution for your use case, the Quality Analyzer can help.

If you're unsure, download both. SVG files are tiny (usually under 5KB), and you can always convert SVG to other formats later. You can't go the other direction — a PNG can't be cleanly converted back to a scalable vector. For format conversion in general, the Format Converter handles raster-to-raster changes.

Print Pitfalls

A barcode that looks perfect on screen can fail completely on a label. The gap between "this looks right" and "this scans reliably" comes down to a few physical constraints.

Quiet zones. Every barcode needs blank space on both sides — at least 10x the width of the narrowest bar. If you crop the barcode image or place it too close to text or graphics on a label, scanners can't locate the start and end patterns. Leave margin.

Minimum bar height. Taller barcodes are easier to scan because the scanner has more vertical space to hit. The generator's height slider controls this — for retail shelf labels, 15mm is standard. For small labels, don't go below 10mm. The Print Readiness Scanner can verify whether your label image meets minimum size requirements.

Contrast. Black bars on white background is the universal standard. Colored bars on colored backgrounds can work — dark blue on white, black on light yellow — but the contrast ratio must be high enough for the scanner's infrared sensor. Red bars on white often fail because many barcode scanners use red laser light, and red bars reflect too similarly to the white background.

Don't stretch horizontally. Resizing a barcode image non-proportionally (stretching it wider without increasing height, or vice versa) changes the bar widths and breaks the encoding. If you need a wider barcode, increase the scale setting and regenerate — don't drag-resize in your label design software.

Use Cases by Format

Inventory tags (Code 128): generate a barcode for each asset — laptops, equipment, furniture. Print on adhesive labels, stick to the item. Scan with any handheld scanner or phone app to pull up the asset record. The barcode value maps to your internal database.

Product labels (EAN-13 / UPC-A): after registering your product with GS1 and getting your GTIN, generate the barcode and include it on your packaging artwork. Download SVG for the print file. Verify it scans by uploading the printed label image to the Barcode Scanner.

Shipping cartons (ITF-14): for cases and pallets. The ITF-14 barcode goes on the outer box, identifying the contents. Typically printed directly on the corrugated cardboard, so thick bars (higher scale) are necessary for reliable scanning through the rough surface.

Library or archive labels (Code 39): still widely used in library management systems. Generate the barcode from the item's catalog number, print on a label, and affix to the book spine or document folder.

Event tickets and badges: Code 128 with a unique ID per ticket. Print the barcode on the ticket or badge. Scan at the door with a handheld scanner or phone app to check against the guest list. Simple, offline-capable, no internet required at the entry point.

Verifying Your Barcode

After generating and printing a barcode, test it before committing to a full print run. Print a single label, photograph it, and upload the photo to the Barcode Scanner. If it decodes correctly and shows the right value, the barcode is good. If it fails, check quiet zones, resolution, and contrast.

For digital barcodes (embedded in a PDF or email), take a screenshot of the barcode area and scan it the same way. If you need to compare barcode quality across different print settings, the Similarity Scanner can show differences between two barcode images side by side.

Common Questions

Do I need a GS1 membership to use this generator? No. Generating the barcode image is free and unrestricted. GS1 membership is only needed if you want a legitimately registered product number for retail distribution. For internal use, prototyping, or personal projects, any number works.

SVG or PNG? SVG for anything printed. PNG for screens. When in doubt, SVG — it scales to any size without quality loss.

What if I get a check digit error? EAN-13, UPC-A, and ITF-14 require a mathematically valid check digit as the last digit. If you're getting an error, the last digit doesn't match the rest of the number. Use a check digit calculator to find the correct value, or verify the number against your GS1 registration.

Can I use these barcodes on Amazon or Walmart? The barcode image will be standards-compliant and scannable. But the number must be a GS1-registered GTIN for those platforms. Amazon and Walmart verify barcode numbers against the GS1 database — a made-up number will be rejected.

Bars, Numbers, Labels

A barcode is one of the simplest tools in commerce — a number translated into a pattern of lines that a machine can read faster than a human can type. The Barcode Generator handles the translation. You handle the number, the format choice, and the printing. Get those right and the barcode does its job — quietly, reliably, billions of times a day, on every shelf and shipping dock in the world.