PNG to normal map means you already have a color texture in PNG and you need tangent-space normals. Upload that file, set strength against the 3D preview, and export a new PNG. JPG and WebP work too, but PNG is the cleaner source.
Convert a PNG
- Open the generator and drop in the PNG.
- Move Normal Strength until grooves read under the preview light without sparkle.
- Leave Invert normal Y off for Roblox, Unity, and Blender. Turn it on for Unreal when the green channel looks inverted.
- Export PNG and import it as non-color data.
Why PNG beats JPG for this
The generator infers slope from color changes. JPEG's 8 by 8 blocks are color changes, so a smooth wall or sky turns into a grid of fake bumps. PNG does not add that grid. If the only file you have is a JPEG, export a PNG from your editor after a light denoise, then convert that. Re-saving a JPEG as PNG does not remove blocks that are already baked in.
What happens to transparency
The alpha channel is not converted into height, roughness, or a mask. Only the RGB color is used. A PNG with a transparent background can pick up a fringe where the edge blends to empty pixels. Composite it onto the background it will actually tile against, then upload the flattened image.
The rest of the material
This page is only the PNG path. The normal map generator covers diffuse, albedo, and photo sources, plus the OpenGL and DirectX choice in more detail. After the normal is believable, add roughness, metallic, and height from the same session.