An SVG has no size of its own — it is instructions for drawing rather than a grid of pixels — so the only real question is how large you want the PNG to be. This page draws it in your browser at twice the size the file nominally asks for, which is what keeps it sharp on a modern screen, and transparency survives intact. The drawing itself is never sent anywhere: only the finished PNG is.
One SVG at a time. Your browser reads it and draws it — the file is not uploaded to do this.
Drawn at twice the nominal size, so it holds up on a high-resolution display, with any transparent areas kept transparent.
The width control decides how many pixels across the finished PNG is. Ask for fewer and the file gets smaller with it.
Step by step, with screenshots: How to turn an SVG into a PNG
Because a drawing does not carry its fonts. Text in an SVG names a typeface and leaves the rest to whatever is reading it, so it is drawn here with the fonts installed on your own device — which may not be the ones the drawing was made with. If the wording has to be exact, convert the text to outlines in your editor before exporting; it then travels as shapes and cannot be substituted. This page tells you when a drawing contains text, so you are never surprised by it afterwards.
Twice whatever size the drawing declares, by default. If it declares none — plenty of SVGs carry only a viewBox — the shape is taken from that instead. The width control then sets the finished size exactly, and the picture keeps its proportions whatever you choose.
Yes. PNG stores transparency properly, so whatever was see-through in the drawing is still see-through afterwards. That is the main reason to choose PNG here rather than JPEG, which has no way to store it and would fill the gaps with solid colour.
The drawing itself is not. It is read and rasterised by your own browser, and only the finished PNG is sent to be optimised. That is unusual on this site — most of the tools here do their work at the far end — and it is a consequence of how the conversion has to be done rather than a feature added on top.
Free Online Image Optimizer