Generate a scannable barcode in seconds
Barcodes remain the backbone of inventory, retail and asset tracking because they are cheap to print and fast to scan. This free barcode generator turns any text or product code into a scannable Code 39 barcode and lets you download it as a PNG — no design software, no sign-up and no watermark.
What Code 39 is and why it is so widely supported
Code 39, sometimes called "Code 3 of 9", was one of the first alphanumeric barcode symbologies and remains one of the most universally recognised. Every character — letters, digits and a small set of symbols — is represented by a fixed pattern of five bars and four spaces, three of which are "wide" and the rest "narrow", which is where the name comes from. Because the format has been an open, unlicensed standard for decades, essentially every barcode scanner ever made can read it, making it a safe default when you are not sure what scanning hardware the other end will use.
How a barcode scanner actually reads bars and spaces
A scanner shines a light across the barcode and measures how much light bounces back as it passes over each bar and space — dark bars absorb light, light spaces reflect it. Because Code 39 defines each character strictly by the relative widths of its bars and spaces rather than their absolute size, the same barcode scans correctly whether it is printed small on a label or large on a sign, as long as the proportions and contrast are preserved.
Where Code 39 barcodes are used
- Inventory and warehouse labels — tracking stock by SKU or item code.
- Asset tags — identifying equipment, tools or fixed assets.
- ID badges and access cards — encoding an identifier for a scanner to read.
- Internal tracking codes — anywhere a simple, universally readable code is needed without a licensing fee.
Printing tips for a barcode that scans reliably
Keep strong contrast — black bars on a white background remain the most reliable combination. Do not shrink the barcode so far that individual bars blur together; leave it large enough for the narrowest bar to stay crisp at your printer's resolution. Preserve the quiet zone — the clear white margin on either side — since scanners use it to find where the barcode starts and ends. Always test a printed barcode with the actual scanner it is intended for before relying on it in production.
How to use the generator
Type the text or code you want to encode — uppercase letters, digits and the supported symbols only — and the barcode renders instantly. Download it as a PNG and drop it straight into labels, packaging or printed documents.
Code 39 versus QR codes — which to choose
Both are free to generate here, but they suit different jobs. Code 39 is a one-dimensional barcode limited to a small character set and a modest amount of data, but it is compact, extremely fast for a laser scanner to read in a single sweep, and supported by decades-old hardware still in use in many warehouses. QR codes are two-dimensional, can hold vastly more data including full URLs, and are read by any smartphone camera without dedicated hardware. If you are encoding a short product or asset code for existing barcode-scanning equipment, Code 39 is usually the right choice; if you want something a customer's phone can scan directly, a QR code is the better fit.
Frequently asked questions
What is Code 39?
Code 39 is one of the oldest and most widely supported barcode formats, capable of encoding uppercase letters, digits and a handful of symbols — readable by virtually any barcode scanner.
Which characters can I encode?
Uppercase letters A–Z, digits 0–9, a space, and the symbols - . $ / + %. Lowercase letters are automatically converted to uppercase since Code 39 has no lowercase symbols.
Will a real barcode scanner read these?
Yes. Code 39 is a long-established industry standard, so standard barcode scanners — including many smartphone scanning apps — read it reliably when printed with reasonable size and contrast.
Is there a watermark or a limit on how many I can make?
No. Generate and download as many barcodes as you like, completely free, with no watermark and no account required.