# mmdc > CLI for mermaid, a diagram generation tool with a domain-specific language. > A mermaid definition file is taken as input and a SVG, PNG, or PDF file is generated as output. > More information: . - Convert a file to the specified format (automatically determined from the file extension): `mmdc {{[-i|--input]}} {{input.mmd}} {{[-o|--output]}} {{output.svg}}` - Specify the theme of the chart: `mmdc {{[-i|--input]}} {{input.mmd}} {{[-o|--output]}} {{output.svg}} {{[-t|--theme]}} {{forest|dark|neutral|default}}` - Specify the background color of the chart (e.g. `lime`, `"#D8064F"`, or `transparent`): `mmdc {{[-i|--input]}} {{input.mmd}} {{[-o|--output]}} {{output.svg}} {{[-b|--backgroundColor]}} {{color}}`