Skip to main content
Support
Docs / MultiMon / Getting Started with MultiMon

Getting Started with MultiMon

Download MultiMon, get past the first-run warning, and put your first clip on screen across every monitor.

MultiMon 1.0.0 is available for Windows and macOS (Apple Silicon). This page takes you from download to a clip playing across your screens.

Download

Download MultiMon 1.0.0-rc.1 for Windows (x64, self-contained zip) — or browse every build on the releases page.

Windows

  • Windows 10 version 1809 or later, or Windows 11, 64-bit.
  • The release is self-contained: .NET 9 is bundled, so there is nothing to install separately.

macOS

First run on macOS

The macOS build is signed with a Developer ID but not yet notarized, so Gatekeeper will refuse a plain double-click the first time. Right-click (or Control-click) MultiMon in Applications and choose Open, then confirm. You only need to do this once. If you prefer the terminal:

xattr -dr com.apple.quarantine /Applications/MultiMon.app

First run on Windows

The Windows build is unsigned, so Windows SmartScreen will warn you the first time you run it. Choose More info, then Run anyway. Code signing is planned, and until it lands this warning is expected rather than a sign that something is wrong.

The main window

MultiMon is one window. There is no menu bar and no settings window; the controls sit on the one surface:

  • a mode dropdown — Span, Individual, Hap or Split
  • an AUDIO DEVICE dropdown, which applies to the whole show
  • a Sync (frame-lock same-length clips) checkbox, shown in Individual mode
  • monitor slots, one per display, where you load your media (Span and Split show a single source field instead)
  • grid rows and columns with an Auto (by screens) tickbox, shown when the mode is Split
  • the inline audio mixer: a MASTER fader and Mute, an Add audio… button, and per-track volume, pan, mute, solo and remove
  • the transport buttons PERFORM and Stop
  • the project buttons New, Open project, Save project and Convert to HAP
  • Identify screens

Step 1 — Choose a mode

ModeWhat it does
SpanOne source sampled across every display MultiMon detects, as one continuous canvas
IndividualA separate source per monitor, with an optional Sync (frame-lock same-length clips) checkbox
HapA separate HAP clip per monitor, all on the one shared clock — tightly frame-synced
SplitOne source cut into a rows-by-columns grid, 2×2 by default

If every clip is a HAP file and the wall has to stay tight, use Hap rather than Individual with Sync: Individual always decodes through Media Foundation, even for a .mov that holds HAP, so it never gets HAP’s frame-accurate decode. Both need clips of equal duration to stay frame-locked.

Step 2 — Load your media

Load a file into a monitor slot. MultiMon plays HAP and HAP Q, and H.264 and HEVC (on Windows these decode through Media Foundation). Accepted containers are mp4, mov, mkv and avi.

Pick your output in the AUDIO DEVICE dropdown — there is one for the whole show, and every track goes to it. For a standalone music bed or stem, press Add audio… in the mixer; it takes mp3, wav, flac, aac and m4a, as well as the audio of an mp4 or mov.

Step 3 — Identify your screens

Press Identify screens and a numbered overlay appears on every display, so you can confirm which physical screen is which before you commit to an assignment. The overlays hide themselves when you enter perform mode.

Step 4 — Perform

KeyWhat it does
F11Toggle perform mode
SpacePause / resume while performing
EscExit perform mode

You can also press PERFORM and Stop in the transport row.

Step 5 — Save the show

Save project writes a .mmproj file — JSON, schema version 2 — holding your monitor assignments, sources and mode. Open project loads one back; a version 1 file is migrated automatically.

Only open .mmproj files you created yourself: the media paths inside a project file are used as written.

Optional: FFmpeg

Convert to HAP shells out to FFmpeg, which must be on your PATH. FFmpeg is not bundled, and no playback feature needs it — this is the one tool that does. Install it only from a source you trust.

Next steps