How a four-tier fallback system fixes reverse image search on Instagram and Facebook

Reverse image search browser extensions work by building redirect URLs to engines like Google Lens or Yandex, rather than uploading image data directly. However, this approach silently fails on platforms like Instagram, Pinterest, and Facebook, which place transparent overlay elements over photos that block standard right-click detection. A developer building a reverse image search extension discovered that using a content script to capture the contextmenu event and call document.elementsFromPoint() can retrieve the actual image beneath the overlay. Additional complications arise when image URLs are blob-scoped, hotlink-protected, cookie-gated, or canvas-rendered, meaning no single method can retrieve all image types. The developer outlined a four-tier fallback system to address each failure mode, progressively escalating from URL-based redirects to fetching raw image bytes when necessary.