EAN-13 Barcode Validator

Run an ean 13 barcode check on supplied product-code batches before catalog imports, marketplace syndication or supplier-data reconciliation. Validate a complete 13-digit code or calculate the missing check digit from a 12-digit base. Export one structured result per processed input, including errors.

This is an algorithm-only utility, not a product scraper. It does not check whether a barcode is assigned by GS1, belongs to a particular product, or is authentic.

Who is it for?

• Catalog operations teams screening supplier barcode columns before an import.
• Retail data engineers building repeatable checksum checks into a pipeline.
• Merchants identifying likely transcription errors before marketplace submission.
• Analysts who need explicit per-row error reasons rather than a single batch verdict.

Why use it?

Keep leading zeros, original input positions and duplicates intact. A checksum mismatch is distinguished from a malformed code, and both appear in the same export as successful checks. Calculation mode produces a completed code without falsely claiming to have verified a supplied check digit.

The Actor uses no external product database, account, proxy or supplier API. Its result is deterministic for a given string, apart from the processing timestamp. Invalid individual codes do not discard the rest of the batch.

Getting started

1. Open the Actor input form.
2. Enter barcode strings, not JSON numbers, in codes.
3. Select validate for full 13-digit codes or calculate for 12-digit bases.
4. Set maxItems if you want only the first part of the batch.
5. Run the Actor and open the default dataset.
6. Export JSON, CSV or Excel-compatible data using Apify's dataset export controls.

{
  "codes": ["4006381333931", "4006381333932", "0123456789012"],
  "mode": "validate",
  "maxItems": 10000
}

The first and third checks pass; the second has an incorrect supplied check digit.

Input parameters

Field	Default	Behavior
codes	Required	Array of 1–10000 strings, each at most 256 characters
mode	validate	Whole-batch operation: validate or calculate
maxItems	20	Global first-N input-entry cap, from 1 to 10000

Leading and trailing whitespace is trimmed. Internal spaces, hyphens, letters and non-ASCII digits are rejected, not silently removed. Zero is not an unlimited setting. Duplicates and invalid entries count toward the cap. The platform charge budget can stop output before the cap.

Unknown input fields, non-string array entries, empty arrays and unsupported modes fail the run with a clear error. There are no URL, file-upload, CSV-input or dataset-import routes: provide the array directly, or prepare it in your upstream application.

EAN-13 barcode check rules

A valid-format EAN-13 contains exactly thirteen ASCII digits. The first twelve digits are weighted alternately 1 and 3 from the left. The expected final digit is (10 - (weightedSum % 10)) % 10.

Validation compares that expected digit with the supplied thirteenth digit. A matching checksum detects many transcription errors, but not all errors; some digit transpositions can remain checksum-valid.

An all-zero string passes the checksum mathematically. It is not evidence of a legitimate assigned retail identifier. Product assignment, restricted prefixes and business-specific forbidden values belong in separate catalog rules.

Calculate a missing check digit

Use exactly twelve digits per entry:

{
  "codes": ["400638133393", "012345678901"],
  "mode": "calculate"
}

The results contain completed codes 4006381333931 and 0123456789012. In this mode providedCheckDigit and isValid are null: there is no supplied check digit to verify. A thirteen-digit entry is a format error in calculation mode; the Actor never guesses a mode per row.

Output fields

Field	Meaning
inputIndex	Zero-based position in the original input array
inputCode	Original string, unchanged
normalizedCode	String after trimming surrounding whitespace
mode	Selected batch operation
formatStatus	valid_format or invalid_format, independent of checksum match
calculatedCheckDigit	Expected digit as a string; null for invalid format
providedCheckDigit	Supplied final digit in valid-format validation; otherwise null
completedCode	Base plus expected digit; null for invalid format
isValid	Validation verdict; null for calculation mode
errorReason	Machine-readable diagnostic; null when successful
checkedAt	UTC ISO 8601 processing timestamp

On a mismatch, completedCode is the checksum-corrected candidate. It does not establish which original digit was mistyped or justify automatically replacing the catalog code.

{
  "inputIndex": 0,
  "inputCode": "4006381333931",
  "normalizedCode": "4006381333931",
  "mode": "validate",
  "formatStatus": "valid_format",
  "calculatedCheckDigit": "1",
  "providedCheckDigit": "1",
  "completedCode": "4006381333931",
  "isValid": true,
  "errorReason": null,
  "checkedAt": "2026-10-28T12:00:00.000Z"
}

The timestamp above is illustrative; all other values match the supplied example's computed result.

Errors and limits

• empty_code: nothing remains after trimming.
• non_ascii_digit: characters other than ASCII 0–9 are present.
• expected_13_digits: validation received the wrong digit count.
• expected_12_digits: calculation received the wrong digit count.
• check_digit_mismatch: format is valid but the final digit is incorrect.

Format diagnostics follow that order: a code containing letters reports non-digit content before length. Validation format errors have isValid: false; calculation format errors retain isValid: null. Every such returned row is billable.

There is no deduplication, pagination or automatic retry against outside services. Larger catalogs can be partitioned into separate batches of up to 10000 entries. Use the original array position to join results back to the source; positions restart for each run.

How much does it cost to validate EAN-13 barcodes?

Pay per event: one start event per accepted run and one item event per returned row, whether the code is valid, invalid or duplicated. Both operations use the same events. No separate calculation fee applies.

The current BRONZE price is $0.001 per run plus $0.0012 per processed barcode. For example:

Returned rows	BRONZE total
1	$0.0022
10	$0.013
100	$0.121

Prices vary by Apify plan tier; see the Actor's current pricing panel. A partial run can incur charges for its emitted rows. Malformed batch configuration is rejected before the start charge. No subscription, outside lookup fee or proxy purchase is required by this Actor.

Integrations

• In a supplier-import job, convert the barcode column into strings, run validation, then quarantine rows with isValid: false.
• Use Apify schedules to recheck newly supplied batches. Scheduling repeats the saved input; this Actor does not discover changed records or keep a historical catalog.
• Export CSV to Excel or Google Sheets, configuring barcode columns as text to avoid stripping leading zeros.
• Use an Apify webhook to notify a downstream application when a run completes, then fetch its dataset and join by inputIndex.
• Combine checksum screening with a separate product lookup when you need product metadata, rather than treating checksum success as identity verification.

API usage

Start a run with your own Apify token:

curl -X POST 'https://api.apify.com/v2/acts/automation-lab~ean-13-check-digit-validator/runs' \
  -H "Authorization: Bearer $APIFY_TOKEN" \
  -H 'Content-Type: application/json' \
  -d '{"codes":["4006381333931"],"mode":"validate"}'

JavaScript with apify-client:

import { ApifyClient } from 'apify-client';
const client = new ApifyClient({ token: process.env.APIFY_TOKEN });
const run = await client.actor('automation-lab/ean-13-check-digit-validator')
  .call({ codes: ['4006381333931'] });
if (run.status !== 'SUCCEEDED') throw new Error(`Run ended: ${run.status}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems({ limit: 100 });
console.log(items);

Python with apify-client:

import os
from apify_client import ApifyClient
client = ApifyClient(os.environ['APIFY_TOKEN'])
run = client.actor('automation-lab/ean-13-check-digit-validator').call(
    run_input={'codes': ['4006381333931']})
if run['status'] != 'SUCCEEDED':
    raise RuntimeError(run['status'])
print(client.dataset(run['defaultDatasetId']).list_items(limit=100).items)

Use the run's returned dataset ID. A start response is run metadata, not the barcode results. Fetch further pages explicitly for exports larger than your chosen page size.

Use with MCP

Configure an Actor-specific subset, not an unqualified growing catalog:

claude mcp add --transport http apify \
  'https://mcp.apify.com?tools=automation-lab/ean-13-check-digit-validator'

Claude Desktop, Cursor, and VS Code setup (use your client's HTTP MCP configuration):

{
  "mcpServers": {
    "apify": {
      "url": "https://mcp.apify.com?tools=automation-lab/ean-13-check-digit-validator"
    }
  }
}

Authenticate using your client's supported Apify authorization flow. Availability depends on Actor access and client capabilities.

Example prompts: “Validate these three EAN-13 strings and show their checksum verdicts without removing leading zeros.” Or: “Calculate the EAN-13 check digit for base 400638133393.” Discover actual names and argument schemas with read-only tools/list; Actor selection also adds run/data/abort helpers, not just a single tool.

For an authorized invocation, start once and keep the run ID and storage IDs. call-actor waits at most 45 seconds (waitSecs defaults to 30); if still running, check the same run with get-actor-run using bounded 2/4/8-second backoff capped at 10 seconds and a 120-second deadline. Set the client request timeout above the selected server wait plus transport margin. Recover a known run after a client timeout, never restart it just to poll. If the ID is unknown, report uncertainty. At the deadline report the pending run ID and stop polling. Terminal failures are failures; any available rows are partial.

After success, read get-dataset-items with explicit dataset ID, limit, offset and needed fields. A reasonable consumer budget is pages of 20 source rows, at most 100 rows or 64 KiB of UTF-8 serialized content admitted to model context, whichever comes first. Enforce byte limits host-side before model injection, including oversized single rows; otherwise do not promise a hard byte guarantee. Track source offsets, report truncation and continuation offsets, and retain full exports outside model context. These are consumer choices, not reduced Actor input limits or universal token-saving guarantees.

Legality, privacy and responsible use

Submit only codes and data you are authorized to process. Do not paste credentials or personal customer information into barcode strings. Results include the original input strings and follow your Apify storage/access settings.

Failed operations send sanitized diagnostic input, exceptions and actor/build/run IDs to our private GlitchTip service for repair. Secret fields and URL queries are removed; reports are retained for 30 days. Avoid sensitive content in arbitrary barcode values even though telemetry is scrubbed.

This tool is not a GS1 registry service, legal certification, fraud detector or compliance approval. Verify product assignment through the appropriate authoritative source before relying on it commercially.

FAQ and troubleshooting

Why did my leading zero disappear? JSON numbers and spreadsheet numeric columns lose formatting before the Actor receives them. Supply quoted strings; lost zeros cannot be reconstructed safely.

Why is a real product marked invalid? Check the original digit count, punctuation and copied characters. This Actor supports EAN-13 only, not EAN-8, UPC-A, GTIN-14 or ISBN-10.

Can a fake code pass? Yes. Checksum validity is only arithmetic consistency, not registration or authenticity.

Does calculation repair my product code? It returns the correct check digit for the supplied twelve digits. It cannot determine whether those twelve digits identify the intended product.

Why are fewer rows returned? Inspect the first-N input cap and the run's terminal status. Also check the platform billing limit. A failed or interrupted run can have partial output. Duplicate codes are not removed.

Can it create barcode images or scan photographs? No. It operates only on supplied digit strings.

Related Actors

Open Food Facts EAN UPC GTIN Lookup resolves food-product metadata from supplied barcodes. Use this validator for arithmetic checks and that separate Actor for product lookup; neither replaces authoritative GS1 assignment verification.