I built a local-first image checker for marketplace sellers

Marketplace sellers often discover image problems too late. A product photo may look fine in an editor, but after uploading it to a marketplace it can become: cropped in search thumbnails too small for zoom previews the wrong aspect ratio for a sales channel risky for Amazon-style main image requirements awkward when reused across Etsy, Amazon, TikTok Shop, Shopify, eBay, or Walmart I wanted a simple preflight step before publishing product images, so I built ListingPic : 👉 https://listingpic.com/ What it does ListingPic is a browser-based marketplace image checker and resizer. You upload a product photo, choose the marketplaces you care about, and get a readiness report covering things like: image dimensions aspect ratio file type file size thumbnail crop risk safe-area positioning marketplace-specific warnings The goal is not to replace manual review. It is to catch obvious image risks before sellers waste time uploading, previewing, deleting, resizing, and re-uploading. Why local-first? A lot of product photos are sensitive: unreleased SKUs private product photography branded assets client images images sellers do not want copied or stored elsewhere So ListingPic processes images locally in the browser. Your images are not uploaded to our server for analysis. That also makes the tool fast for quick checks: drop in an image, review the warnings, adjust before publishing. Current checkers The MVP includes marketplace-focused checks for: general marketplace readiness Etsy image checks Amazon product image checks TikTok Shop image checks There are also entry points for Shopify, eBay, and Walmart workflows. Example use case Imagine you have one product photo and want to reuse it across multiple channels. ListingPic can help answer: Is the image large enough? Will the product be cut off in thumbnails? Is the image close enough to square for a channel that prefers square previews? Is the product too close to the edge? Do I need a separate crop for Etsy or TikTok Shop? D