Marketplace Image ToolkitLocal batch image prepUpload images

About

A batch tool for people who sell in more than one place

Version 1.0.0. Built because preparing the same twenty photos for three marketplaces meant doing the same work three times, and every tool wanted the images on someone else’s server first.

What it does

One upload, one crop decision, one naming rule — and a set of outputs that matches what each marketplace actually accepts. Amazon gets a 1600 px JPEG with transparent areas flattened onto white, Etsy gets a flattened JPEG because it cannot take transparency, Shopify gets WebP because it can. Opaque backgrounds are never altered — there is no background removal or replacement. The whole thing is a single HTML page plus a Web Worker, and it never talks to a server about your images.

How the platform rules are sourced

Every preset is a data object, not hard-coded logic, and each rule carries the official URL it came from plus the date it was checked. Where a platform does not publish a number, the rule is marked unverified instead of filled in from memory.

Updating a rule means editing one object in src/data/marketplaces.ts. No component reads a magic number directly, which is what keeps the checklist and the preset from disagreeing.

What it deliberately does not do

  • No account system, no signup, no email capture.
  • No AI features — no background removal, no upscaling models, no generative fills.
  • No server-side storage of your catalogue.
  • No claim of platform certification or endorsement. It is not affiliated with Amazon, Etsy or Shopify.
  • No promise that a passing checklist means a listing will be approved.

Known gaps

Per-image crop overrides, per-platform format overrides and a target-file-size search are not implemented. Payments are scaffolded but not connected. The full list lives in docs/KNOWN-ISSUES.md in the repository, including the items that were tested and the ones that were not.

Marketplace data last reviewed 2026-11-03.

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