← Barcode generator

Generate a barcode with curl

Make product and shipping barcodes: EAN-13, EAN-8, UPC-A, UPC-E, Code 128, Code 39, Code 93, ITF-14 and Codabar, as PNG or SVG. Here is the whole call with curl, with the output it produced when we ran it.

Before you start

An API key. Create a free account; it comes with free tokens every month. Put the key in an environment variable so it stays out of your code: export BLOODWEB_KEY=your_key
curl 7.76 or later (for --fail-with-body, which makes curl stop on an error and still show the reason).

The code

Save it as barcode-generate.sh and run bash barcode-generate.sh.

curl -sS --fail-with-body \
  -H "Authorization: Bearer $BLOODWEB_KEY" \
  "https://bloodweb.net/api/v1/barcode-generate?type=ean13&data=590123412345" \
  -o barcode.png

What you get

Tested 19 October 2026: this exact code ran against our test copy of the API, which runs the same service code as bloodweb.net, and produced this.

It writes barcode.png: a PNG image, 230 × 106 pixels, 2 KB.

Change the call

Every option the Barcode generator takes. Add or change them the same way as the ones in the code.

data required: What to encode. For EAN and UPC, leave off the check digit and it is added; include it and it is verified.
type: Symbology. One of: code128, code39, code93, ean13, ean8, upca, upce, itf14, codabar.
format: Image format. One of: png, svg.
bar_width: Width of the narrowest bar in pixels. 2 or more for printing.
height: Bar height in pixels.
text: Print the human-readable value under the bars.
color: Bar colour.
background: Background colour, or "transparent".

If it fails

A failed call is not charged. The answer is JSON with an error object; curl stops with an error, and that JSON lands in barcode.png instead of the result, so open it as text to read the reason. The usual ones:

401 missing_key or invalid_key: BLOODWEB_KEY is not set in the shell that runs the code, or the key was revoked.
400 bad_param: a value is wrong or missing. The message names the parameter.
402 insufficient_tokens: the balance does not cover the call. Top up in the dashboard.
429 rate_limited: too many calls at once. Wait the seconds in the Retry-After header and send it again.

Every code and its fix is in the docs.

The Barcode generator page: every option, the limits, and Try it now in your browser.
Getting started: keys, errors and rate limits for all the services.