Image File Size

Tiny image file-size labels measured from existing requests. No duplicate downloads.

See how much your images weigh, right where they appear. Image File Size adds small B / KB / MB labels to images on a web page. It measures the page's existing image requests, so it does not download the images again. HOW TO USE 1. Open a web page and click the extension icon, or press Alt+Shift+I. 2. Turn on “Monitor this tab”. 3. Reload the page to measure images that were already loaded. 4. Hover over a label, or focus it with the keyboard, to see more details. 5. Turn monitoring off to remove the labels and stop observing requests. WHAT YOU CAN SEE • Encoded image file size, excluding response headers. • Resource size and the actual bytes transferred by the latest request. • Intrinsic and displayed image dimensions. • Cache source, load time, and time to first byte when Chrome reports them. • MIME type, HTTP content encoding, and srcset availability. • Bytes per displayed megapixel, with optional colors to help spot heavy images. Choose the value shown on the badge and the details you want to see. Display preferences are saved locally and apply to monitored tabs. IMPORTANT NOTES Monitoring is opt-in for each tab. Only images loaded after monitoring starts can be measured. Chrome shows a debugging banner because the extension uses the debugger API to observe existing network requests, including cross-origin images. Some cached images and partial responses have no available file size and show “—”. CSS background images, images inside shadow roots, and Chrome's internal pages are not supported. Size-per-megapixel colors are a helpful heuristic, not an image-quality score. PRIVACY Measurements are processed locally. The extension has no analytics or backend and does not upload page data or image contents. Display preferences are stored on your device. See the privacy policy for the information accessed while monitoring. Requires Chrome 126 or newer.