How to use Barcode Generator
- 1
Open the Barcode Generator
Go to tools.slaytic.com and open the Barcode Generator. No sign-up or account required.
- 2
Enter your text or number
Keep it short, since every character adds width to the printed barcode.
- 3
Download the PNG
Save the image, ready to place on a label or document.
- 4
Print and test
Check it scans at your intended print size, keeping clear margins either side.
How this works in your browser
Code 128 encodes each character as a pattern of bars and spaces of varying widths, drawn from three overlapping character sets that let the encoder switch between numeric, upper-case and full ASCII modes to keep the barcode as compact as the data allows. A checksum character is computed and appended so a scanner can reject a misread rather than returning a wrong value silently. The pattern is rendered onto a canvas in your browser and exported as PNG. Two properties follow directly from the format: width grows with every character, since each one occupies real horizontal space, and the quiet margin either side is functionally part of the barcode, because a scanner uses it to find where the pattern begins.
Barcode Generator vs. traditional online converters
| Feature | Barcode Generator (in-browser) | Traditional online converters |
|---|---|---|
| File upload required | No - never leaves your device | Yes - file is sent to a server |
| Processing queue | None - starts instantly | Often, especially at peak times |
| Watermark on output | Never | Common on free plans |
| Usage limits | None - free, unlimited use | Often capped per day or file size |
| Works offline once loaded | Yes, for most tools | No - requires a live connection |
| Account required | No | Often, for anything beyond a trial |
Who uses Barcode Generator
Inventory and stock tracking
Label items with scannable codes for a warehouse or stockroom system.
Shipping and logistics labels
Generate reference codes for parcels, pallets and internal despatch.
Asset and equipment tagging
Mark equipment with codes that link to your own records.
Event and library systems
Produce scannable identifiers for tickets, passes or catalogued items.
Frequently asked questions
Which barcode format does this generate?
Code 128, a widely supported format for text and numeric data used in shipping, inventory, and retail.
Can I include letters as well as numbers?
Yes, Code 128 supports both letters and numbers.
What format does the barcode download as?
A PNG image, ready to print or embed in a document.
Can I use this to make a retail product barcode?
Not for sale through shops. Retail barcodes use UPC or EAN numbers issued by GS1, and the number itself must be registered to you, otherwise it collides with someone else’s product. Code 128 is the right choice for your own internal tracking, labelling and logistics, where you control what the numbers mean.
Why does my barcode not scan?
Usually size or contrast. A 1D barcode needs enough width for the scanner to resolve individual bars, plenty of quiet space either side, and genuine black on white. Printing too small, adding colour, or cropping the margins are the three reliable ways to break one.
How much data can Code 128 hold?
In principle a fair amount, but each additional character adds width, so a long string produces a barcode too wide to print usefully. Keep to short identifiers, typically under twenty characters, and put the detail in a database keyed by that identifier.
Should I use a barcode or a QR code?
A barcode for anything read by existing warehouse, retail or logistics scanners, which are built around 1D formats. A QR code when the reader is a phone, or when you need to encode more than a short identifier.