Image Automation That Just Works

SyncList handles the hardest part of cross-listing: images. Our background proxy bypasses CORS restrictions, auto-converts formats, and uploads images directly to each marketplace's file input — no saving, no dragging, no uploading.

CORS-Safe Background Proxy

Marketplace websites block cross-origin image requests for security. SyncList's background service worker acts as a proxy — fetching images from eBay's servers within the extension context where CORS restrictions don't apply, then passing the binary data to the content script.

  • Background fetch bypasses all CORS restrictions
  • Images auto-upgraded to maximum eBay resolution
  • Supports up to 20 images per product
  • Automatic retry on network failures

Native DataTransfer API Upload

SyncList doesn't use hacks or workarounds to upload images. It creates real File objects from the proxied image data, constructs a proper DataTransfer object, and dispatches native 'change' and 'drop' events on each marketplace's file input element.

This means the marketplace's React/JavaScript code processes the images identically to a manual drag-and-drop — triggering all the correct validation, preview generation, and upload flows.

Optimized for Each Marketplace

Facebook Marketplace

Targets the photo upload grid, dispatches change events on the hidden file input, and waits for Facebook's preview thumbnails to confirm successful upload before proceeding.

Depop

Identifies Depop's drag-and-drop zone, creates synthetic DragEvent and Drop events with the correct DataTransfer payload. Supports Depop's multi-image upload flow.

Mercari / Poshmark / Whatnot

Each marketplace has its own DOM structure for image uploads. SyncList detects the correct input element and dispatches platform-appropriate events with proper file naming.

Never Manually Upload Images Again

SyncList's image automation saves the most tedious step of cross-listing. Try it free for 7 days.

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