The latest articles on DEV Community by qiang liu (@qiang_liu_61bcd5dc8419b5f). https://dev.to/qiang_liu_61bcd5dc8419b5f https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.us-east-2.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F3577740%2Ff8c8009b-1c81-4af4-bd13-113a4067ae12.png https://dev.to/qiang_liu_61bcd5dc8419b5f en qiang liu Wed, 12 Aug 2026 09:49:05 +0000 https://dev.to/qiang_liu_61bcd5dc8419b5f/i-built-a-local-first-image-checker-for-marketplace-sellers-31i1 https://dev.to/qiang_liu_61bcd5dc8419b5f/i-built-a-local-first-image-checker-for-marketplace-sellers-31i1 <p>Marketplace sellers often discover image problems too late.</p> <p>A product photo may look fine in an editor, but after uploading it to a marketplace it can become:</p> <ul> <li>cropped in search thumbnails</li> <li>too small for zoom previews</li> <li>the wrong aspect ratio for a sales channel</li> <li>risky for Amazon-style main image requirements</li> <li>awkward when reused across Etsy, Amazon, TikTok Shop, Shopify, eBay, or Walmart</li> </ul> <p>I wanted a simple preflight step before publishing product images, so I built <strong>ListingPic</strong>:</p> <p>👉 <a href="https://listingpic.com/" rel="noopener noreferrer">https://listingpic.com/</a></p> <h2> What it does </h2> <p>ListingPic is a browser-based marketplace image checker and resizer.</p> <p>You upload a product photo, choose the marketplaces you care about, and get a readiness report covering things like:</p> <ul> <li>image dimensions</li> <li>aspect ratio</li> <li>file type</li> <li>file size</li> <li>thumbnail crop risk</li> <li>safe-area positioning</li> <li>marketplace-specific warnings</li> </ul> <p>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.</p> <h2> Why local-first? </h2> <p>A lot of product photos are sensitive:</p> <ul> <li>unreleased SKUs</li> <li>private product photography</li> <li>branded assets</li> <li>client images</li> <li>images sellers do not want copied or stored elsewhere</li> </ul> <p>So ListingPic processes images locally in the browser.</p> <p>Your images are not uploaded to our server for analysis.</p> <p>That also makes the tool fast for quick checks: drop in an image, review the warnings, adjust before publishing.</p> <h2> Current checkers </h2> <p>The MVP includes marketplace-focused checks for:</p> <ul> <li>general marketplace readiness</li> <li>Etsy image checks</li> <li>Amazon product image checks</li> <li>TikTok Shop image checks</li> </ul> <p>There are also entry points for Shopify, eBay, and Walmart workflows.</p> <h2> Example use case </h2> <p>Imagine you have one product photo and want to reuse it across multiple channels.</p> <p>ListingPic can help answer:</p> <ul> <li>Is the image large enough?</li> <li>Will the product be cut off in thumbnails?</li> <li>Is the image close enough to square for a channel that prefers square previews?</li> <li>Is the product too close to the edge?</li> <li>Do I need a separate crop for Etsy or TikTok Shop?</li> <li>Do I need to manually review Amazon main image requirements?</li> </ul> <h2> What I learned while building it </h2> <p>A few product lessons stood out:</p> <ol> <li><p><strong>Sellers do not think in pixels first.</strong><br><br> They think in terms like “will this upload?”, “will the product be cut?”, and “will this hurt my listing?”</p></li> <li><p><strong>Different marketplaces create hidden image work.</strong><br><br> A single photo may need different crops or checks depending on where it is published.</p></li> <li><p><strong>Privacy matters even for small tools.</strong><br><br> Local browser processing is a strong default for tools that touch product photos.</p></li> <li><p><strong>The hardest part is not just resizing.</strong><br><br> It is explaining image risks in a way that non-technical sellers can act on quickly.</p></li> </ol> <h2> What I am improving next </h2> <p>I am still iterating on the tool and would love feedback from developers, indie makers, and marketplace sellers.</p> <p>Possible next improvements:</p> <ul> <li>clearer platform-specific recommendations</li> <li>better examples of risky vs safe crops</li> <li>batch checking multiple images</li> <li>downloadable marketplace-ready variants</li> <li>more detailed guides for Etsy, Amazon, TikTok Shop, Shopify, eBay, and Walmart</li> </ul> <p>If you sell on marketplaces or build tools for ecommerce sellers, I would love to know:</p> <ul> <li>What image checks are missing?</li> <li>Would batch processing be more useful than a single-image checker?</li> <li>Which marketplace image rules are the most painful in practice?</li> </ul> <p>You can try it here:</p> <p>👉 <a href="https://listingpic.com/" rel="noopener noreferrer">https://listingpic.com/</a></p> <p>Thanks for reading — feedback is very welcome.</p> ecommerce webdev tools indiehackers