Only useful if continuously using Views rewrite results, see <a href=':url2'>#2908861</a>. Inputting this means having trouble with `data:image` placeholder being stripped out by Views sanitization procedures causing 404. Will override global 1px `data:image` placeholder, including core Responsive image 1px `data:image` with this so to avoid 404, and independent from the previous `Responsive image 1px placeholder` option. Must be URL, e.g.: /blank.gif or /blank.svg. Be warned: unlike .svg, browsers have display issues with 1px .gif, see <a href=':url1'>#2795415</a>. Alternatively use <code>hook_blazy_settings_alter()</code> for more fine-grained control. Leave it empty to use default inline SVG or Data URI to avoid extra HTTP requests. If you have 100 images on a page, you will save hammering your server with 100 extra HTTP requests by leaving it empty. The <b>blank.svg</b> content sample if not using blank.gif: <br><code>&lt;svg xmlns='https://www.w3.org/2000/svg' viewBox='0 0 100 100'/&gt;</code><br>Save it at Drupal web root as <code>blank.svg</code>, and reference it as <code>/blank.svg</code> in the Placeholder field.