Bulk Barcode from CSV
Turn a pasted list or CSV column into a printable sheet of barcodes.
Values — one per line, or a CSV column
How this test page works
Values are read one per line or from a chosen CSV column, encoded as Code 128, and laid out on a real page size at real millimetre dimensions. The number worth watching is the narrowest bar, and the reason it matters here more than on a single barcode is that a sheet prints at one size: the longest value in the list determines the module width for every label on it. So one unusually long code quietly makes every other barcode on the sheet narrower than it needed to be, and below about 0.19 mm per module laser printers stop holding the bar edge cleanly.
What the results mean
- Narrowest bar
- One module. Governed by the longest value in the list, since all labels print at one size.
- Grid
- Columns by rows that fit the page at your sizes.
- Print scaling
- Must be 100%. Shrinking narrows the bars as well as the grid.
- SVG bars
- Drawn as vectors so edges reach paper exactly. Bitmap barcodes lose the edge and stop scanning.
Common problems and fixes
- Some codes scan and others do not
- Check the narrowest bar width. The longest value sets the module size for the whole sheet, so a single long code can push everything below what scanners read.
- The barcodes look fine but will not scan
- Almost always print scaling or bitmap resampling. Print at 100% and never screenshot a barcode.
- My CSV column is wrong
- Set the column number. Quoted fields containing commas are handled, but a mismatched quote runs rows together.
Frequently asked questions
Why does one long value affect the whole sheet?
Because every label prints at the same width. The longest value needs the most modules, so it sets the module size, and every other barcode inherits it.
How narrow can bars be?
Keep the narrowest above about 0.19 mm. Below that the limit is your printer holding the edge rather than the design, and scanners start failing.
Why SVG rather than an image?
Because a barcode resampled through a bitmap loses its edges, and blurred edges are the most common cause of a printed barcode that will not scan.