Check image size and dimensions

Image dimensions, type, and file size

Use this image inspector to see file type, pixel dimensions, file size, aspect ratio, and megapixels before you compress, convert, or resize. Performance reports say improve images. They do not say whether you are looking at a 6 megapixel PNG of a sunset or a 64-pixel icon saved as JPEG at quality 100.

Aspect as a reduced ratio catches the 1000x667 that is "almost 3:2" and the 1200x1200 that will be crushed into a 1.91:1 preview. Megapixels tell you if resize is mandatory. Bytes per pixel tell you if the codec is wrong. Then leave: compress, convert, resize, or generate srcset.

We do not dump GPS here. If you need it gone, remove the EXIF. If you need colors, use the picker. This page is facts for the next click.

JavaScript to read image dimensions from a File

The inspector wraps what the browser already knows about a local File. Useful if you are wiring your own dropzone.

const img = new Image();
img.onload = () => {
  const mp = (img.naturalWidth * img.naturalHeight) / 1e6;
  const bpp = file.size / (img.naturalWidth * img.naturalHeight);
  console.table({
    type: file.type,
    width: img.naturalWidth,
    height: img.naturalHeight,
    megapixels: mp.toFixed(2),
    bytes: file.size,
    bytesPerPixel: bpp.toFixed(2),
  });
  URL.revokeObjectURL(img.src);
};
img.src = URL.createObjectURL(file);

<img src="unknown.png" alt="" width="WID" height="HGT">