How to create a barcode
Creating a barcode image is the easy part, and any generator does it in about ten seconds. The reason barcodes fail is almost always one of the five decisions around it.
Step 1. Decide who has to read it
Everything else follows from this one answer, so resolve it before you touch a generator.
If a retailer, a marketplace or a distributor scans it, you need a GTIN registered with GS1. That is a number issued to your company, not one you choose. Without it the barcode will scan and the listing will still be rejected.
If only your own scanners read it, there is no registration, no fee and no external requirement at all. The number just has to be unique inside your own system. Warehouse bin labels, asset tags, internal SKUs and work-in-progress tracking all sit here.
Work through it
Tick these off as you go. This resets if you reload the page, so treat it as a working pad rather than a saved record.
0 of 6 done
Step 2. Choose the symbology
Symbology means the barcode language. Picking the wrong one is the most common cause of a code being rejected downstream.
- Internal stock, asset tags, bin labels: Code 128. Takes letters and digits, compact, no registration.
- Retail checkout: UPC-A in North America, EAN-13 elsewhere.
- Shipping cartons: ITF-14.
- Small parts, instruments, circuit boards: Data Matrix.
- Legacy systems and government processes: Code 39, because almost everything reads it.
Step 3. Get or create the number
For retail, apply to your national GS1 organisation, receive a company prefix or a block of numbers, and assign one to each distinct product. Distinct means each size, colour and pack configuration separately, not each product line. The full process, and what it costs you to get wrong.
For a whole range of codes at once, the bulk generator takes a list, a CSV or a numbered sequence. For internal use, design a scheme that stays readable to a human as well as a scanner. Something like WH2-A04-BIN12 tells a picker where they are standing; 0000000000417 does not. Code 128 lets you do the first, which is a large part of why it is the default choice for internal work.
Step 4. Generate the image
Enter the value and let the encoder handle the check digit. For UPC-A, EAN-13 and ITF-14 you can enter one digit short and the check digit gets calculated. If you enter the full length, a good generator verifies the digit rather than accepting it silently, which is how you catch a transcription error before it reaches a printer.
Export SVG when your label software takes it, since vector stays sharp at any size. Use PNG at a print resolution otherwise, and never rescale it non-proportionally afterwards.
Step 5. Size it to the specification, not to the label
This is where most printed barcodes go wrong. Two numbers matter.
The X-dimension is the width of the narrowest bar and it drives everything else. GS1 publishes a minimum, a recommended value and a maximum per symbology. Shrinking below the minimum to fit a template is the single most common cause of a code that renders perfectly and scans badly.
The quiet zone is the blank margin either side. UPC-A needs at least nine times the X-dimension on both sides. ITF-14 needs ten. Artwork creeping into that margin breaks the scan even though the bars are untouched.
The published size limits for each symbology.
Step 6. Test before you print the run
Print one label on the actual printer, on the actual material, and scan it with the actual reader. Not a phone, unless a phone is what will be used in production.
If a printed code still fails, work through why a barcode will not scan, which covers each cause in order. Three things only show up at this stage: ink spread on absorbent material like corrugated board, low contrast from a tired thermal printer, and curvature on a bottle or tube that flattens the bars at the edges. None of them are visible on screen.
Sources
Every specification figure on this page traces to one of the following. Nothing is stated here that could not be checked against them.
- GS1 General Specifications size limits, as published by GS1
- GS1, GTIN allocation and registration process, via your national GS1 member organisation
Last reviewed 6 September 2026
This guide is written and maintained by Cedrick Reese at Ready Utilities. The symbology recommendations reflect the intended use each specification defines rather than preference, and the sizing guidance reproduces limits published in the GS1 General Specifications, rechecked when this page is updated. Registration fees are deliberately not quoted here because GS1 pricing is set per country and revised over time. The failure modes described in step 6 are common practical causes rather than specification requirements, and are described as such.
Common questions
How do I create a barcode for my product?
If the product is sold at retail, you first need a GTIN registered with GS1, then you render it as a UPC-A or EAN-13. If the barcode is only scanned inside your own business, you can skip registration entirely and use Code 128 with any value that is unique in your system.
Can I create a barcode by myself?
Yes. Generating the image takes seconds and needs no special software. The part you cannot do yourself is register a retail product number, which has to come from GS1.
How much does it cost to create a barcode?
Generating the image costs nothing. A GS1-registered number for retail sale carries a fee that varies by country and by how many numbers you need, so check your national GS1 organisation for current pricing.
Can I create barcodes on my phone?
Yes. This generator runs in a mobile browser and the download works the same way. The harder part on a phone is printing at a controlled size, which matters more than the generating.
Is there a free app to generate barcodes?
You do not need one. A browser-based generator does the same job without installing anything, and keeps the value you type on your own device.