How to use: Barcode Check Digit Validator

Description

Validate EAN-8, EAN-13, UPC-A and ITF-14 barcodes and see the weighted sum step by step.

• Validators & Checksums
• Because everything is computed client-side, Barcode Check Digit Validator is safe to use with sensitive data such as API keys, tokens or private logs.

How to use

Using Barcode Check Digit Validator takes three steps:

1. Paste your data into the input box (or load the example).
2. Configure the options to match your target format or scenario.
3. Copy, download or inspect the output — it updates live as you type.

Run

Examples

A valid EAN-13. UPC-A, EAN-8 and ITF-14 use the same modulo-10 rule with different weights.

Input

4006381333931

Output

EAN13  4006381333931

Digits: 13
Weighted sum of the payload: 89
Expected check digit: 1
Actual check digit:     1
Result: ✓ VALID

Weights applied (left to right, excluding the check digit):
  4×1 + 0×3 + 0×1 + 6×3 + 3×1 + 8×3 + 1×1 + 3×3 + 3×1 + 3×3 + 9×1 + 3×3

Modulo-10 check digit is shared by EAN, UPC, ITF-14, GTIN and ISBN-13.

This output was produced by actually running the tool, not written by hand.

Use cases

Common situations where Barcode Check Digit Validator helps:

• Validate EAN-8, EAN-13, UPC-A and ITF-14 barcodes and see the weighted sum step by step.

Parameters

This tool has no options — it works on the input alone.

FAQ

Good to know

• Everything runs client-side, so extremely large inputs are limited by your browser tab’s memory rather than by a server upload limit.

Related tools

Barcode Check Digit Validator → · Validators & Checksums →