Enable in After Effects
Turn on PreviewMonitor as a Mercury Transmit device in After Effects — and what transport control can and cannot do there.
After Effects uses the same plugin as Premiere Pro, so the live picture works identically. Enable it in Video Preview preferences. Transport control is a different story — read the limits below before you rely on driving playback from the phone.
Enable the device
| Platform | Menu path |
|---|---|
| Windows | Edit → Preferences → Video Preview |
| macOS | After Effects → Preferences → Video Preview |
Adobe renamed this menu to Settings in the 2025 releases. These docs say Preferences throughout; if your build says Settings, it is the same item.
Turn on Mercury Transmit
Mercury Transmit is the master switch. With it off, no device streams.
Mercury Transmit has to be on and PreviewMonitor ticked — one without the other does nothing.
Tick PreviewMonitor as the device
The device is listed as PreviewMonitor.
If it is not in the list, quit and reopen After Effects — plugins are scanned once, at launch.
Open a composition
After Effects only pushes frames when a comp is actually rendering to the viewer. With no comp open, the phone shows Waiting for video and stays black. That is correct behavior, not a fault.
Two separate devices on one machine
If both Premiere Pro and After Effects are running with PreviewMonitor enabled, your iPhone sees two entries — each labelled with its host app, each with its own control port and its own pairing. You connect to one at a time. See Two hosts on one machine.
What works, and what does not
This is the honest version. An After Effects user who expects the phone to drive their preview the way it drives Premiere Pro will be disappointed.
| Capability | In After Effects |
|---|---|
| Live picture | Works fully — same plugin, same quality, same settings |
| Audio | Does not work at all. See below. |
| Layouts, safe zones, pinch-zoom, save frame | Work — those are all client-side |
| Transport control | Limited. See below. |
Audio
There is no audio path in After Effects. The plugin's After Effects side handles no audio whatsoever — not on the free tier, not on Pro, on neither platform. There is nothing to enable and no setting that changes it.
Worse, the phone cannot tell. The app assumes a host has audio until the plugin says otherwise, and the After Effects side never says otherwise, so the speaker button stays in its ordinary state instead of turning orange. It looks like a working mute toggle and delivers permanent silence. See No audio.
Transport control
Premiere Pro gets true transport control from the separate Control Surface plugin, which both installers ship. After Effects has no Control Surface host, so it needs a different bridge: an AEGP plugin called PremiereLiveAE.aex.
PremiereLiveAE.aex ships in no installer. It is Windows-only, its install path is specific to each After Effects version, and it has to be placed by hand. On macOS it does not exist at all — it is not built for that platform.
Without the bridge — which is every stock installation today — every button falls back to synthetic keystrokes. On Windows those go through SendInput, into the system input queue, so After Effects has to be the foreground application or the keystroke lands in whatever window does have focus. On macOS the fallback posts events into After Effects' own event queue instead, so the foreground barrier does not apply the same way.
The keystrokes are Premiere Pro's keymap, and in After Effects they do not all mean what you want:
- Play/Pause sends Space, which is play/pause in After Effects too.
- Step forward / step back one frame send the left and right arrow keys. In After Effects those nudge the selected layer, they do not step the playhead. The comp frame-step keys are Page Down and Page Up.
- Go to In point / Go to Out point send Shift+I and Shift+O, which have no equivalent meaning in After Effects.
Because the arrow keys move a selected layer in After Effects, tapping the frame-step buttons on the phone against a stock After Effects install modifies your composition — it shifts the selected layer one frame in time. The playhead does not move, so the picture on the phone is identical and nothing tells you it happened. Undo is the only way back. Deselect all layers before using the phone's transport in After Effects, or install the bridge.
With the bridge installed, frame stepping and the two jumps run through the real AEGP API and behave correctly, and the two outer buttons genuinely go to the composition's start and its last whole frame. Play/pause is still a Space keystroke, because After Effects exposes no API to start or stop a preview — but the bridge posts it directly to After Effects' panel window and flips the application's active flag first, so it works even when After Effects is minimized. Nothing on this path needs After Effects in front.
There is no shuttle. The app declares five transport commands and none of them is a shuttle, so no shipping build can send one to any host — After Effects included. The plugin's shuttle opcodes exist in the protocol only.
For the full picture of how transport is routed on each host, see Transport control. For a workflow written around these constraints, see the After Effects artist guide.
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Enable in Premiere Pro
Turn on the PreviewMonitor device in Premiere Pro's Playback preferences — Video Stream, Audio Stream, background output, and the Setup window.
Connect your iPhone
Pair the PreviewMonitor iPhone app with your Mac or PC — auto-discovery, the Local Network permission, the QR code, the pairing code, and manual IP entry.