Barcode Generator at a glance
- What it does
- Generate scannable barcodes in Code 128, Code 39, EAN-13, UPC-A and other formats, and download them.
- Where it runs
- Entirely in your browser — no data is uploaded
- Works offline
- Yes, once the page has loaded
- Cost
- Free, with no account and no usage limit
- Category
- Generators & Security
How to use the barcode generator
- Choose a format. Code 128 is the right default for internal use; retail products need EAN or UPC.
- Enter the data. Each format has rules about length and permitted characters - see below.
- Adjust the size so it will print large enough to scan.
- Download the image and place it on your label.
Which format to use
| Format | Accepts | Use for |
|---|---|---|
| Code 128 | Any ASCII, variable length | The general-purpose choice. Compact, dense, used throughout logistics. |
| Code 39 | A-Z, 0-9, a few symbols | Older, less dense, still standard in defence and automotive. Widely readable by old scanners. |
| EAN-13 | Exactly 13 digits | Retail products outside North America. Requires a registered GS1 prefix. |
| EAN-8 | Exactly 8 digits | Small retail packaging where EAN-13 will not fit. |
| UPC-A | Exactly 12 digits | Retail in the US and Canada. A subset of EAN-13. |
| ITF-14 | 14 digits | Shipping cartons and outer cases. |
| Codabar | Digits and a few symbols | Libraries, blood banks, photo processing. |
If you are selling a product
Retail barcodes are not arbitrary. EAN and UPC numbers are issued by GS1, the organisation that administers the global numbering system, and a retailer will not stock a product whose barcode is not properly registered - the number must resolve to your company in the central database.
You obtain a company prefix from your national GS1 office, then assign product numbers within it yourself. The final digit is a check digit computed from the others, which is what lets a scanner detect a misread.
Barcodes sold cheaply by resellers were typically issued to a different company before GS1 changed its licensing terms. They may scan, but they identify someone else, and major retailers reject them.
Printing barcodes that actually scan
Most scanning failures are print problems rather than data problems.
- Quiet zone. Leave clear space either side - at least ten times the narrowest bar width. Crowding the barcode against other artwork is the most common cause of failure.
- Contrast. Black on white. Scanners read reflected red light, so red bars can be invisible to them, and light bars on a dark background fail on many devices.
- Size. Do not shrink below about 80% of nominal for EAN and UPC. Below that, print imprecision starts to matter.
- Print at native resolution and avoid rescaling a bitmap, which blurs bar edges. Vector output is safer.
- Avoid glossy laminate directly over the code, which reflects the scanner's beam.
- Test with a real scanner at the size and on the material you will actually use.
Barcode or QR code?
A linear barcode stores data in one dimension and typically holds up to about 20-25 characters usefully. It is read by dedicated scanners, is compact on a label, and is what every retail and warehouse system expects.
A QR code is two-dimensional, holds thousands of characters, includes error correction that tolerates damage, and can be read by any phone camera. That last point is decisive for anything a customer will scan - a URL, a menu, a payment link. The QR generator handles those.
Use a barcode for inventory, assets and retail. Use a QR code for anything involving a phone.
Frequently asked questions
For internal use, yes. For retail, the number must be registered to you through GS1, or retailers will refuse it. This tool renders any number you supply; it cannot register one.
Usually the quiet zone, contrast or size. Check for clear space either side, use black on white, and print large enough. Blurred bars from a rescaled bitmap are the other frequent cause.
The last digit of an EAN or UPC, calculated from the preceding digits. Scanners recalculate it and reject the read if it does not match, which catches most misreads.
Code 128. It accepts letters and numbers, is compact, and every modern scanner supports it. Code 39 is worth considering only if you must support very old equipment.
No. The barcode is rendered in your browser and the image is generated locally.
Nothing you enter here leaves your browser
Barcode Generator does its work in JavaScript running on your own device. The page loads once, and after that there is no upload step and no server involved — which matters here because a generated password or key is worthless the moment a third party has a copy of it.
You can verify this rather than taking our word for it: load the page, disconnect from the internet, and the tool keeps working. Our privacy policy sets out what is and is not collected, and this guide explains why the distinction matters.