Code 39 Barcode Generator
Generate a Code 39 barcode for labels, badges, inventory tags and industrial parts from digits, capital letters and a few symbols. Code 39 is self checking and widely used in manufacturing, defense and healthcare. The tool validates the characters, draws the barcode as a PNG image or an SVG file and lets you adjust the scale, the bar height and the printed text.
Frequently asked questions
Which characters does Code 39 support?
Standard Code 39 encodes digits 0 to 9, capital letters A to Z, space and the symbols - . $ / + %, which is 43 characters. Lowercase letters and other symbols are refused with a message. This tool accepts up to 60 characters.
Do I type the asterisks?
No. The asterisk is the Code 39 start and stop character and the tool adds it at both ends automatically. Entering an asterisk yourself is rejected because it cannot appear inside the data.
Why are lowercase letters rejected?
Lowercase letters need the Full ASCII extension of Code 39, which encodes each one as a pair of characters that a scanner has to be configured to combine. To avoid unreadable labels the tool encodes standard Code 39 only. Use the Code 128 Barcode Generator for mixed case text.
Does Code 39 have a check digit?
Code 39 is self checking, so a check character is optional and most applications leave it out. This tool draws the data without an extra check character, which is what scanners expect by default.
Should I download the Code 39 barcode as PNG or SVG?
Choose SVG for print work, packaging artwork and anything you scale later, because the bars stay sharp at every size. Choose PNG for documents, web pages and label software that only accept raster images. The PNG has a white background and the SVG draws a white background rectangle, so both scan on any page color.
Why is Code 39 so wide?
Each Code 39 character uses 9 bars and spaces with a gap between characters, so it needs more room than Code 128 for the same text. Long texts at a high scale can exceed the 4000 pixel limit, and the tool then asks for a lower scale or shorter text.
What do the scale and height settings do?
The scale from 1 to 10, default 3, multiplies the width of every bar. The bar height takes 5 to 50 millimeters and defaults to about 25 millimeters when left empty.
Can I hide the text under the barcode?
Yes. Turn off the human readable text option to draw bars only. The printed text helps people type the value when a scan fails, so keep it on most labels.
Where is Code 39 used?
Code 39 is common in automotive and defense part marking, employee badges, library and asset tags and hospital labels. Its simplicity makes it easy to print with any printer and to read with basic scanners.
Is my input saved?
No. The text is only used to draw the barcode and is not kept after the image is returned.