A free online barcode generator turns a number or short piece of text into a scannable image you can print on labels, shelves, folders or equipment. The harder part is not making the image. It is choosing a format that your scanner can read and, if you plan to sell in shops, using a number that is legitimately yours. This guide covers both, using the formats the QRSnap Barcode Generator actually offers.
How to generate a barcode online
QRSnap's Barcode tab creates one barcode at a time, right in your browser:
- Open the generator and select the Barcode tab.
- Type your value into Barcode value.
- Pick a Barcode type: Code 128, EAN-13, UPC-A, Code 39 or ITF-14.
- Press Generate Barcode and check the preview.
- Choose a resolution (720px, 1024px, 2048px or 4K). The tool notes that larger sizes print sharper.
- Choose JPEG, PNG or WEBP, then download.
If the value does not suit the chosen format, for example letters in a numeric-only format, the tool shows a message suggesting Code 128 instead of producing a broken image. Barcodes are not downloaded as SVG or EPS in this tool, so plan on PNG for most uses.
Choosing the right barcode format
Barcode formats (symbologies) are not interchangeable. Each one limits what characters it can hold, how long the value must be, and who is expected to scan it.
| Format | What it holds | Typical use |
|---|---|---|
| Code 128 | Letters, numbers and symbols | Inventory, SKUs, serial numbers, internal IDs |
| Code 39 | Uppercase letters, numbers and a few symbols | Asset tags, industrial and equipment labels |
| EAN-13 | 13 digits | Retail products outside North America and worldwide |
| UPC-A | 12 digits | Retail products in the US and Canada |
| ITF-14 | 14 digits | Cartons and outer shipping cases |
Code 128 vs. Code 39
Code 128 handles the full range of lowercase and uppercase letters, numbers and symbols, and is generally more compact for the same data. Code 39 is older and simpler, limited to uppercase letters, digits and a few symbols, and still turns up in industrial and asset-tracking workflows. If you are starting from scratch and only need to identify your own items, Code 128 is usually the safer default. One caution: Code 128 is the symbology, while GS1-128 adds extra GS1 data rules on top of it. QRSnap generates standard Code 128 and does not offer GS1-128 data structures.
EAN-13 vs. UPC-A
The two are close relatives. A 12-digit UPC-A can be written as a 13-digit EAN-13 by adding a leading zero, and modern retail scanners read both. Choose UPC-A if your retail partners work mainly in the US and Canada, and EAN-13 if they work elsewhere. Both are fixed-length numeric formats, so the number of digits has to match what the format expects.
A barcode image is not a registered product number
This is the point most generator pages skip. A generator draws the bars for whatever valid number you type. It does not give you ownership of that number.
- Selling through shops or marketplaces: retail numbers (UPC and EAN, both part of the GTIN family) are issued through GS1. Inventing a number can duplicate one that already belongs to another company. GS1 UK warns that using a number registered to someone else can get your listings delisted on marketplaces.
- Internal use only: if the barcode will only be scanned in your own shop, warehouse or office, you can assign your own codes, ideally in Code 128 or Code 39, and keep a list of what each one means.
So the sequence for retail is: obtain a legitimate number first, then generate the barcode image from it.
Creating barcodes for product labels and inventory
- Give every variant its own code. A different size or colour of the same product is a different item to a scanner.
- Keep the code short and consistent. Shorter values make a wider-barred, easier-to-read barcode at a given label size.
- Record the meaning. Keep a spreadsheet that maps each barcode value to a product, shelf or asset.
- Mind the batch size. QRSnap generates one barcode at a time, which suits a handful of labels. For hundreds of labels, dedicated label software with batch printing will save time.
Downloading and printing barcodes
Download the highest resolution you can use, and place the image in a document or label template without stretching it. Scale it proportionally so the bars keep their intended width ratios, and print at 100% scale rather than letting the print dialog "fit to page".
For retail EAN and UPC symbols, GS1's symbol reference specifies a magnification range of 80% to 200% (bar width roughly 0.26 to 0.66 mm), with 150% to 200% recommended for automated scanning. Tiny labels are the most common reason a technically valid barcode fails.
Improving barcode scan reliability
- Leave blank space on both sides. This margin is called the quiet zone. A common rule for linear barcodes is at least 10 times the width of the narrowest bar.
- Use strong contrast. Dark bars on a plain white background are the safest combination.
- Print crisply. Blurry or smudged edges make bars merge. Use a good print resolution and avoid very fast, low-quality printing.
- Do not shrink it too far. Make the barcode as large as the label allows.
- Test before you print a run. Scan a printed sample with the same scanner or phone app your team will actually use.
Common barcode generation problems
- The tool rejects my value. You may have picked a numeric format for text, or entered the wrong number of digits. Switch to Code 128 for general text, or match the digit count the format expects.
- It looks fine on screen but will not scan on paper. Check size, quiet zone, contrast and print sharpness first. Glossy laminate, curved bottles and low-quality labels can also hurt scanning.
- The scanner reads the wrong data or nothing. Some scanners need a particular symbology enabled. Confirm that your scanner is set up to read the format you chose.
- The number does not match what a retailer expects. That is a registration issue, not a generator issue. See the GS1 section above.
Barcode generator vs. QR code generator
A standard barcode stores a short identifier that a system then looks up. A UPC-A, for instance, holds only 12 digits. A QR code can store much more, including web addresses and contact details. Use a barcode when a scanner or point-of-sale system expects one, and a QR code when you want people to open a link with their phone. If that is what you need, use QRSnap's QR code generator.
Frequently asked questions
Is the QRSnap barcode generator free?
Yes. QRSnap's tools are free to use, and the barcode generator runs in your browser without an account.
Which barcode format should I use for inventory?
Code 128 is a sensible default because it holds letters and numbers compactly. Code 39 is also common for asset labels. Use EAN-13 or UPC-A only for retail items with a legitimately assigned number.
Can I make my own UPC for selling on a marketplace?
You can draw a barcode from any valid digits, but a made-up number is not registered to you and may clash with another company's product. For retail or marketplace listings, get your numbers through GS1.
Why won't my barcode scan?
The usual causes are a missing quiet zone, low contrast, a barcode printed too small or blurry, a scanner that does not have that format enabled, or a value of the wrong length for the format.
Can I download my barcode as an SVG?
Not from this tool. Barcodes download as PNG, JPEG or WEBP. Choose PNG at the highest resolution for printing.
Does QRSnap create batches of barcodes?
No. The tool creates one barcode at a time. For large label runs, use dedicated label or inventory software.