Do these tools work for Amazon, eBay, and Shopify, or just one marketplace?

All of them. The Marketplace Image Checker has rule sets for Amazon, eBay, and Shopify specifically; the identifier, barcode, and CSV tools produce standard GS1/ISO formats that every marketplace accepts, since none of them invent their own barcode or GTIN standard.

Is any of this product data uploaded anywhere?

No. Every tool in this toolkit runs entirely in your browser - product names, SKUs, prices, and images are processed on your own device and never transmitted anywhere, the same guarantee as every other tool on this site.

Can I use this to fix a real marketplace listing rejection?

Yes - that's the most common reason people land on the Product CSV Validator and Marketplace Image Checker specifically. Paste the rejected row or drop the flagged image in, and the specific rule that failed is called out directly.

Does the Barcode Generator produce real, scannable codes?

Yes, standard EAN-13, UPC-A, CODE128, and ITF-14 barcodes that scan correctly - but the underlying numbers are only real if you already own a licensed GS1 prefix. For a genuinely new product line, get identifiers issued through GS1 first, then use this to generate the label artwork.

Available for contract & consulting work

+91 86559 88773 WhatsApp contact@websync.in

Start a project

Ecommerce Toolkit

Prepare product data for any marketplace

Eight free tools, one connected workflow: generate identifiers, build labels, validate your catalog CSV, check images, and produce test banking data - in the order a real listing actually needs them, all in your browser.

Step 01

Generate Product Identifiers

Before a product can go live on Shopify, Amazon, or any marketplace, it needs stable identifiers - a SKU your own systems can track, and a GTIN/EAN/UPC the marketplace itself requires to accept the listing. Get these right before you build out variants; changing an identifier after a listing is live usually means re-submitting it for review.

SKU Generator

Generate consistent SKU codes in bulk from a custom pattern with variant permutations, sequential numbering and collision checking.

EcommerceOpen Tool

GTIN Converter

Convert product codes between GTIN-8, GTIN-12 (UPC-A), GTIN-13 (EAN-13) and GTIN-14, validate check digits, and normalise a whole catalog in bulk.

EcommerceOpen Tool

EAN / UPC Generator

Generate valid-checksum EAN-13, EAN-8, UPC-A and GTIN-14 product codes in bulk for test catalogs, and validate the check digit of any existing code.

EcommerceOpen Tool

Step 02

Create Product Labels

Once you have a barcode number, you need a scannable label for the physical product or shipping carton - warehouse staff and marketplace fulfillment centers scan the label, not the number printed next to it.

Barcode Generator

Render a scannable EAN-13, UPC-A, CODE128 or ITF-14 barcode from a product code and download it as a PNG for labels and store listings.

EcommerceOpen Tool

Step 03

Validate Marketplace Data

Most listing rejections happen at the CSV upload step, not the marketplace's manual review - a missing column, a duplicate SKU, or one malformed barcode can fail an entire batch. Catch it before you upload, not after.

Product CSV Validator

Check a product CSV for missing columns, broken variant handles, duplicate SKUs, invalid barcodes and bad prices before you import it.

EcommerceOpen Tool

Step 04

Validate Product Images

Amazon, eBay, and Shopify each enforce their own dimension, aspect-ratio, and background rules. A listing can be otherwise perfect and still get flagged because one image is 50px too small or has the wrong background.

Marketplace Image Checker

Check product images against each marketplace's dimension, aspect ratio, file size and format rules before you upload them.

EcommerceOpen Tool

Step 05

Banking & Payments

Testing a payment or payout integration needs realistic-looking account data that's guaranteed not to belong to a real account - format-valid, checksum-correct, and clearly test data.

IBAN Generator

Generate format-valid, checksum-correct IBAN numbers for any supported country for testing and QA, and validate the checksum of any IBAN.

EcommerceOpen Tool

Real scale, not a demo

We build the systems behind catalogs like this

Beyond these free tools, WebSync builds and maintains the automation behind real multi-marketplace catalogs - 7M+ records ingested per pipeline, 50+ marketplaces and channels integrated, orders synced across systems around the clock.

Talk to us about your catalog See a related case study

Ecommerce toolkit FAQ

Questions about this workflow

What this toolkit does and doesn't do, and when to bring in a licensed identifier.

Need the whole catalog pipeline built, not just checked?

From one-off validation to automated, scheduled syncs across every marketplace you sell on.

Book a free consult