Run FFmpeg in Background on Windows with Start

Running long video encoding or audio processing tasks with FFmpeg can tie up your command prompt. This article explains how to use the Windows start command to run FFmpeg as a background process, allowing you to free up your terminal or run multiple conversion tasks simultaneously without blocking your workflow.

To run FFmpeg in the background using the Windows Command Prompt (cmd.exe), you can use the start command with specific switches depending on how you want the background process to behave.

Method 1: Run in the Same Window (Background Execution)

If you want FFmpeg to run in the background of your current Command Prompt window and immediately regain control of your prompt, use the /B switch.

Because FFmpeg continuously outputs progress text, you should redirect its output to a log file. Otherwise, the text will clutter your screen while you try to type other commands.

Use the following command structure:

start /B ffmpeg -i input.mp4 output.mp4 > ffmpeg_log.txt 2>&1

• start /B: Starts the application in the background of the current console window without creating a new window.
• ffmpeg -i input.mp4 output.mp4: Your standard FFmpeg command.
• > ffmpeg_log.txt 2>&1: Redirects both standard output (stdout) and standard error (stderr) to a text file named ffmpeg_log.txt. This keeps your console clean and lets you monitor progress by opening the text file.

Method 2: Run in a Separate Minimized Window

If you prefer to have the process run entirely outside of your current command prompt session, you can launch FFmpeg in a separate, minimized command window using the /MIN switch.

Use the following command structure:

start "" /MIN ffmpeg -i input.mp4 output.mp4

• start: The command launcher.
• "": An empty set of double quotes. The start command treats the first quoted string it sees as the window title. Providing an empty title prevents Windows from misinterpreting your file paths or FFmpeg arguments as the window title.
• /MIN: Starts the new window minimized to the taskbar. FFmpeg will run silently in the background, and the window will close automatically when the processing is complete.