A practical guide
Read the measurements before deciding what to change.
The image size checker inspects a JPG, PNG, or WebP without creating a new image. After local decoding, it reports pixel width and height, simplified aspect ratio, megapixels, byte size, and MIME type. These measurements answer different questions: dimensions describe the pixel grid, while bytes describe the storage or transfer weight of this particular file.
A wide image is not automatically a large file, and two images with identical dimensions can have very different byte sizes because their formats, encoder settings, and visual complexity differ. Use the measurements to compare an upload requirement with the actual source before resizing, compressing, or converting. The checker does not currently report reliable color-space or camera metadata.