Image Size Checker and Dimension Inspector

What it reports

It reports pixel dimensions, file size in both readable and exact form, the file type, and the aspect ratio. Between them those answer most questions about whether an image is suitable for a given place on a page.

Read locally, not uploaded

The browser file reader opens it, which is a local operation. Nothing is sent. That distinction matters when the image is a client asset, an unreleased product photograph or anything else under a confidentiality agreement, because with most online tools you cannot tell the difference from the outside.

A note on file size

Large images cause more slow pages than anything else. If an image is several megabytes, it almost certainly needs compressing before it goes on a website, regardless of how good it looks.

Dimensions against display size

An image needs roughly twice its displayed size to stay sharp on a high-density screen, and no more. Anything beyond that is bytes the visitor downloads and never sees the benefit of, which is one of the most common causes of a slow page.

Need this handled across a whole website? See our Backend Web Development and Custom Web Apps page.