DWG opens only in CAD software, and a file saved by a newer AutoCAD can fail to open in an older one. PNG keeps every pixel exactly and supports transparent backgrounds. DWG is at home in architectural plans, mechanical parts and engineering layouts that are still being edited; PNG is the usual choice for screenshots, logos, graphics with text or transparency. The result is a picture of each page, so its text can no longer be selected or searched.
The defaults suit most files. Under Options you can resize the result.
The drawing is shown as its model space, fitted to the extents of what is in it. If model space is empty, the first layout that has objects is drawn instead. Objects on layers that are switched off or frozen are not drawn. It reads AutoCAD DWG files from R13 (1994) to the 2018 format that AutoCAD 2018 to 2025 use; older and newer files are refused with a message. The PNG is 2400 pixels on its longer side unless a size is chosen under Options, on a white background unless another colour is chosen; AutoCAD's colour 7 is drawn black on a light background and white on a dark one. The browser has none of the fonts a drawing names, so text is drawn in a built-in font with Latin, Greek and basic Cyrillic letters and the usual symbols (m², Ø, ±, °). Chinese, Japanese and Korean text appears as empty boxes.