How to Start and Stop Screen Recording from the Command Line

What you need before using the controller

1. Download and extract the current FastCast portable ZIP.
2. Keep fastcast.exe and fastcastc.exe together.
3. Open fastcast.exe and choose capture, audio, quality, and output settings.
4. Leave the FastCast window running; the controller does not launch it automatically.
5. Open PowerShell in the extracted FastCast folder.

The controller uses the same validation and state guards as the Record button and the global Ctrl+Alt+F9 hotkey. It will not bypass a missing source or invalid configuration.

Start a recording from PowerShell

Run:

.\fastcastc.exe --start-record

FastCast starts with the source and settings currently selected in its window. Keeping configuration in the GUI makes the automation command short and prevents scripts from silently changing audio, quality, or output choices.

Choose which monitor to record

To select Display 2 as the command starts the recording:

.\fastcastc.exe --start-record --monitor 2

The number maps to the display numbering FastCast receives from Windows. Verify the selected screen in the FastCast preview before relying on it for unattended capture. An unknown monitor number is rejected rather than silently recording a different screen.

Stop the recording and check the result

Run:

.\fastcastc.exe --stop-record

Wait for FastCast to finalize the MP4. Its Last recording panel reports the file, validation result, size, and any warning, with Open and Show in folder actions. For the full manual workflow, see how to record your screen on Windows.

Check exit codes in a PowerShell script

& .\fastcastc.exe --start-record --monitor 2
if ($LASTEXITCODE -ne 0) {
  throw "FastCast could not start recording."
}

# Run the task you need to capture here.

& .\fastcastc.exe --stop-record
if ($LASTEXITCODE -ne 0) {
  throw "FastCast could not stop recording."
}

Harmless no-ops return exit code 0—for example, asking an already-recording instance to start again. Invalid arguments, an unavailable monitor, or a real control failure return nonzero. Separate Start and Stop calls are safer for automation than a toggle because the desired end state is explicit.

Troubleshooting command-line recording

• FastCast is not running: launch fastcast.exe, finish setup, and retry. The controller intentionally leaves nothing running in the background.
• Command not found: run it as .\fastcastc.exe from the extracted folder or provide the complete quoted path.
• Monitor rejected: confirm the display number in the FastCast Screen list and reconnect or enable any missing monitor.
• Recording will not start: inspect the FastCast window for its validation message. Source, output folder, encoder, or audio setup may need attention.
• Recording stutters: test hardware encoding and lower resolution or frame rate using the recording performance guide.