Why is my lowercase text uppercase in the result?
That is the symbology, not a bug: Code 39 folds case, so the reader reports what a real scanner observes. Full-ASCII payloads belong to Code 39 Extended.
Free tools · Barcodes
Read any Code 39 in the frame.
Code 39 per ISO/IEC 16388 for logistics, badges and work-order labels — lowercase reads back uppercase per the symbology. Nothing leaves your browser.
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Questions
Code 39 Reader & Scanner, answered.
If you manage servers by hand, see the engineering services behind this tools series.
What do the result details show?
Format, reader engine, transmitted bytes with hex and Base64, charset and symbology identifier, plus symbol geometry and bounding box — all in the Payload and Symbol disclosures.
Why did my Code 39 fail to read?
Wide inter-character gaps matter: keep the start/stop asterisks (or A–D frame for Codabar cousins) in frame and avoid cropping the quiet zones.
Are my images uploaded?
No. Pixels and decoded payloads stay in memory on this device. The page makes no network requests with your data and clears the result after ten idle minutes.
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