How to generate the check digit and SVG for an EAN-13 barcode

1. Enter 12 digits

   "Digits (12)" expects the GS1 prefix + manufacturer code + item reference — 12 numeric characters without the final check digit. Any non-digits in the field are stripped before counting.

2. Press Run

   Result returns `code` (the 13-digit barcode with computed check digit appended), `check` (the check digit alone), and `svg` (a tiny inline SVG of the bar pattern).

3. How the check digit is computed

   Multiply digits at odd positions by 1 and even positions by 3, sum, take mod 10, subtract from 10 (mod 10 again). It's the standard GS1 algorithm — the same one used for UPC-A, ITF-14, and GTIN-13.

4. What this isn't

   The SVG output is a minimal bar pattern for inspection — NOT a print-resolution, GS1-compliant barcode with quiet zones, guard bars, and exact module widths. For label printing use a real barcode library that respects ISO/IEC 15420.