Barcode generator
A barcode generator draws the bars or squares that a scanner reads from a number or text you give it. Opo Codes has more than 80 barcode types in one free generator that runs in your browser: retail, books, shipping, GS1 and 2D codes. It checks the scan before you print, and it does not issue official product numbers.
Open the generatorFree. Runs in your browser.
How to do it
- Open the generator and choose a family, or search by use, such as carton or pharmacy.
- Type the number or text. Types that need a check digit add it for you or show the right one.
- Look at the VERIFIED stamp, then set the bar width, bar height and quiet zone if your label needs it.
- Choose PNG, JPG, SVG or PDF and a resolution, then download.
Which barcode for which job
Retail: EAN-13 for shop shelves almost everywhere, UPC-A for North America, EAN-8 for very small packs. Books: ISBN, plus ISSN for magazines. Logistics: Code 128 for any text on a shipping label, Code 39 for simple asset tags, ITF-14 for cartons, GS1-128 for batch, expiry and pallet data.
2D codes hold far more in less space and need a camera-style scanner. Data Matrix suits small parts and electronics, PDF417 suits passes and records, and GS1 DataMatrix carries product data for healthcare. There are also GS1 DataBar, postal, banking and healthcare families in the picker.
One product, four barcodes
Say a tea tin is stocked in your own shop. The shelf label is an EAN-13 such as 2012345678903, an in-store number whose last digit is the check digit. A case of 12 tins gets an ITF-14 such as 12012345678900: a leading 1 for the packaging level, the first 12 digits of the shelf number, and a new check digit, which here is 0.
The courier tag can be Code 128 holding any text, for example OPO-0001. A tiny part inside the tin lid could carry a Data Matrix with the same text. Same product, four jobs, four types, and the same free generator.
What makes a barcode scan
The generator draws the code and reads it back. A VERIFIED stamp means the scan returned exactly what you typed. Formats this browser cannot read, such as UPC-E and Code 93, are marked Not scan-tested, so test a printed copy for those.
Keep dark bars on a light background, because a light code on a dark one is flagged. Contrast under 4.5 to 1 gets a warning, a bar width under 0.25 mm gets a warning, and the default 0.33 mm is the retail standard. Leave the quiet zone, the empty margin: 11 bar widths is the default for bar codes.
Export as PNG, JPG, SVG or PDF. For pictures choose 150, 300 or 600 DPI. SVG and PDF stay sharp at any size, which is the safer choice for print. The serial option makes up to 500 numbered codes at once.
Honest limits
This tool encodes what you supply. It does not issue GS1 numbers or ISBNs. A number you sell with in shops has to come from the issuing body, because an invented one can clash with someone else's product. Numbers starting with 2 are for use inside your own shop only.
Questions
Which barcode type should I choose?
Use the one your buyer, courier or marketplace asks for. If nobody asks, EAN-13 for shop shelves, Code 128 for labels with letters, and Data Matrix for very small items are the usual picks.
Is it free, and do I need an account?
It is free and needs no account. The barcode is drawn in your browser.
Can I make a QR code here too?
Yes. QR is in the same picker, and the QR code generator has more options for links, Wi-Fi and contacts.
How do I know a printed barcode will scan?
The generator reads each code back and shows VERIFIED when it matches. Still scan one printed copy with your own scanner before a big run.