What this barcode generator does
A barcode is a number or a short text written as bars and spaces that a scanner can read in a fraction of a second. This barcode generator turns your value into one of six common symbologies, works out the check digit when the format needs one, and gives you a vector SVG for print or a PNG for documents and web pages. Everything is calculated in your browser, so your product numbers stay on your computer.
Which barcode type should you use?
- EAN-13 - the standard retail barcode in most of the world. 13 digits: a GS1 company prefix, your item number and a check digit.
- UPC-A - the 12 digit retail barcode used in the US and Canada. A UPC-A is an EAN-13 with a leading zero, so scanners worldwide read both.
- EAN-8 - a short 8 digit retail code for very small packs, issued separately by GS1.
- Code 128 - a compact code for any ASCII text: letters, digits and symbols. It is the usual choice for shipping labels, warehouse locations, asset tags and internal SKUs.
- Code 39 - an older code for uppercase letters, digits and a few symbols. It is wide, but many industrial and badge systems still expect it.
- ITF-14 - the 14 digit code printed on outer cartons and cases. It tolerates rough corrugated board, which is why it often has a thick frame called bearer bars.
For a quick rule: if the barcode will be scanned at a store checkout, use EAN-13 or UPC-A with a number you own. If it only needs to work inside your own business, Code 128 is usually the best fit.
Free barcodes vs GS1 numbers
The barcode image is free to make. The number inside a retail barcode is not something a website can give you. Retailers and marketplaces check that EAN and UPC numbers (GTINs) belong to the brand, and the official source is GS1, the non-profit that runs the system. You license a company prefix from your local GS1 office and then number your own products. This tool does not issue numbers. It turns a number you already have into a correct barcode, and it can check that the digits are valid.
For internal use, such as stock rooms, libraries, tool cribs or event tickets, you can use any numbering you like with Code 128 or Code 39. No registration is needed.
How check digits work
EAN, UPC and ITF-14 end with a check digit so a scanner can catch a misread. The GS1 method is short: starting from the rightmost digit of the number without its check digit, multiply the digits by 3, 1, 3, 1 and so on, add the results, and take the amount needed to reach the next multiple of 10.
Example for the EAN-13 number 590123412345: the weighted sum is 5x1 + 9x3 + 0x1 + 1x3 + 2x1 + 3x3 + 4x1 + 1x3 + 2x1 + 3x3 + 4x1 + 5x3 = 83. The next multiple of 10 is 90, so the check digit is 7 and the full code is 5901234123457. Type 12 digits into the tool and it adds the digit for you. Type all 13 and it tells you if the last one is wrong. Code 128 has its own built-in checksum, which the generator always adds. Code 39 can carry an optional mod 43 check character.
Printing tips that save a reprint
- Keep the quiet zone. Leave clear space on both sides, at least 10 times the narrowest bar. Text or a box edge that touches the bars is a common reason a code will not scan.
- Use dark bars on a light background. Black on white is safest. Red bars are invisible to many laser scanners, and inverted codes fail on a lot of hardware.
- Do not squash it. Scale the barcode evenly. Stretching only the width or the height changes the bar ratios. The SVG keeps edges sharp at any size.
- Mind the minimum size. Retail EAN-13 codes are designed around about 37 x 26 mm at 100 percent. Small sizes need a good printer.
- Test before a full run. Print one sheet and scan it with the scanner your team or retailer uses, or with a phone scanning app.
Labels also need words that sell. Pair your codes with copy from the free product description generator, bill wholesale customers with the free invoice generator, or browse every free AI generator and tool on KissMySkills.
FAQ
Is this barcode generator free?
Yes. There is no sign-up, no watermark and no limit on single barcodes. Bulk mode handles up to 500 values at a time. Everything runs in your browser, so your numbers are never uploaded.
Can I use these barcodes to sell in stores or on Amazon?
The barcode images are standard and scannable, but retailers and marketplaces also check who owns the number. For retail EAN or UPC codes you need GTINs licensed from GS1 for your brand. Enter your GS1 number here and the tool creates the correct barcode for it.
What is a check digit and do I need to add it?
A check digit is the last digit of an EAN, UPC or ITF-14 number. It lets scanners detect a misread. You do not need to calculate it: enter the number without it and the tool adds it, or enter the full number and the tool tells you if the last digit is wrong.
Should I download SVG or PNG?
Use SVG for print, packaging and label software, because it is a vector file and stays sharp at any size. Use PNG for documents, spreadsheets and web pages. Pick 4x resolution for a PNG that will be printed.
Which barcode is best for inventory and internal labels?
Code 128 is usually the best choice. It encodes letters, digits and symbols, it is compact, and almost every scanner reads it. Use Code 39 only if an older system requires it.