Business Tools
Planning aids for scoping projects and choosing what to build on. 19 free tools - every one runs entirely in your browser, nothing you paste in or upload ever leaves your device.
An interactive stack recommender for scoping a new project, plus a connected set of tools for generating and validating the identifiers, barcodes, and catalog data marketplaces require before a listing goes live.
Stack Selector
Select your project scope, budget, and features to instantly receive a vetted, modern tech stack and service recommendation.
IBAN Generator
Generate format-valid, checksum-correct IBAN numbers for any supported country for testing and QA, and validate the checksum of any IBAN.
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.
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.
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.
ISBN / ASIN Validator
Validate ISBN-10 and ISBN-13 check digits, convert between them, and check Amazon ASIN format in bulk.
SKU Generator
Generate consistent SKU codes in bulk from a custom pattern, with variant permutations, sequential numbering and collision checking. Free, no sign-up.
Product CSV Validator
Check a product CSV for missing columns, broken variant handles, duplicate SKUs, invalid barcodes and bad prices before you import it.
Marketplace Image Checker
Check product images against each marketplace's dimension, aspect ratio, file size and format rules before you upload them.
GST Calculator
Add or remove GST at any standard slab rate, split into CGST/SGST for intra-state supply or IGST for inter-state supply.
Profit Margin Calculator
Work out margin and markup from cost and selling price, roll shipping and duty into a per-unit landed cost, or back into the price a target margin needs.
Discount Calculator
Work out stacked/sequential discounts, a Buy-X-Get-Y-free offer's real effective discount, and whether a bundle price beats buying items individually.
Shipping Cost Calculator
Work out volumetric vs actual chargeable weight and the total shipping cost from your own courier's rate card, including fuel surcharge and COD fees.
COD & RTO Cost Calculator
Work out your own RTO rate, what a single return-to-origin actually costs, and how COD's net revenue per order compares to a discounted prepaid option.
Marketplace Fee Calculator
Enter your marketplace's commission, payment gateway, and shipping fees to see the real net payout and margin behind a listing price.
GSTIN Validator
Validate an Indian GSTIN in your browser: length, pattern, state code and the 15th-character checksum, with the exact failing check named.
UPI QR Code Generator
Turn a UPI ID into a standard UPI intent QR code and download it as a PNG. Leave the amount blank so the payer enters their own.
WooCommerce CSV Validator
Check a WooCommerce product CSV before you import it: missing columns, duplicate SKUs, orphaned variations and malformed prices, by row.
Shopify ⇄ WooCommerce CSV
Convert a product CSV between Shopify and WooCommerce column formats in either direction, with every dropped column listed explicitly.
Choosing the right tool
Stack Selector is a standalone planning tool, unrelated to the rest. The e-commerce tools - IBAN, EAN, Barcode, GTIN, ISBN/ASIN, SKU, CSV Validator, Image Checker - form a connected workflow; see the Ecommerce Toolkit for the order they're actually used in.
Common use cases
- Scoping a new web project's tech stack before committing to a build
- Generating and validating product identifiers before a marketplace listing goes live
- Producing test banking data for a payment integration's test suite
Business FAQ
Do the generated IBANs, barcodes, and identifiers work on real bank accounts or real products?
IBANs are format-valid and checksum-correct but not tied to any real account - they're for testing only. Barcodes and GTINs are real, standard-format numbers, but only legally yours to use on an actual product if you already hold a licensed GS1 prefix.