AutoFreeMemory

ComfyUI-AutoFreeMemory

Automatically unloads Models and Execution Cache once ComfyUI's queue has been idle for a configurable number of seconds — the equivalent of Ollama's keep_alive=N, built as a native ComfyUI plugin.

No graph node to wire up: it runs silently in the background from the moment ComfyUI starts, and is configured entirely from ComfyUI's own Settings menu (with an optional topbar shortcut).

Features

• Idle-triggered auto-free — frees VRAM/RAM after N seconds of an empty queue, so a workflow you forgot to close doesn't sit there holding memory.
• Same effect as the native "Unload Models and Execution Cache" button — not a partial workaround. It goes through the exact same mechanism, so it also clears cached node outputs (images, latents, etc.), not just the loaded models.
• Zero-friction configuration — everything lives in Settings > AutoFreeMemory: no config file to hand-edit, no restart required for a setting to take effect.
• Optional topbar button — a one-click shortcut that opens a small popup mirroring the same controls, for quick access without digging through the Settings menu. Can be hidden if you prefer a clean topbar.
• Re-enable safety net — turning the plugin back on after it was disabled immediately frees memory if the queue is idle, instead of waiting for a full idle cycle.
• No dependencies — pure Python standard library + ComfyUI's own APIs. Nothing to pip install.

Installation

Via ComfyUI-Manager (recommended):

Open the Manager → Custom Nodes Manager → search for AutoFreeMemory → Install, then restart ComfyUI.

Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/Nlepetit/ComfyUI-AutoFreeMemory.git

Then restart ComfyUI. In the console log you should see:

[AutoFreeMemory] watchdog started - settings available in Settings > AutoFreeMemory.

Configuration

Open ComfyUI's Settings menu (gear icon) → AutoFreeMemory:

| Setting | Default | Description | |---|---|---| | Enabled | on | Turns the watchdog on/off. | | Idle delay (seconds) | 30 | How long the queue must stay empty before freeing. | | Poll interval (seconds) | 3 | How often the watchdog checks the queue state. | | Show topbar button | on | Shows/hides the topbar quick-access button. |

All changes apply live — no restart needed.

The topbar button (vacuum icon, next to ComfyUI's own settings/view buttons) opens a small popup with the first three controls above, for quick access without opening the full Settings menu.

Environment variable defaults

If you'd rather set a starting value from your launch script (before main.py runs) instead of the Settings UI, these variables act as defaults the first time the plugin runs:

| Variable | Default | Description | |---|---|---| | COMFYUI_AUTOFREE_ENABLED | 1 | 0 to disable by default | | COMFYUI_AUTOFREE_IDLE_SECONDS | 30 | idle seconds before freeing | | COMFYUI_AUTOFREE_POLL_INTERVAL | 3 | check frequency (seconds) |

How it works

A background thread polls PromptServer.instance.prompt_queue (the same queue the UI and the /queue HTTP API use) every "Poll interval" seconds. Once it's been empty (no job running or pending) for longer than the "Idle delay", the plugin sets the same unload_models / free_memory flags on that queue that ComfyUI's native "Free model and node cache" button / POST /free endpoint set. ComfyUI's own main loop then unloads all models and resets the executor's cached node outputs — exactly as if you'd clicked the button yourself, just automatic and without an HTTP round trip.

As soon as a new prompt is queued, the timer resets. Re-enabling the plugin after it was off also triggers an immediate free if the queue is idle at that moment, rather than waiting for a full idle cycle.

Settings are read from ComfyUI/user/default/comfy.settings.json, the standard location ComfyUI uses for a single-user install. If you run ComfyUI with --multi-user, only the default profile is used.

Requirements

• Any reasonably current ComfyUI install (any frontend from 2025+): the plugin relies on ComfyUI's settings extension API and its app.menu.settingsGroup topbar extension point.
• No Python package dependencies beyond ComfyUI itself.

License

MIT