Save Audio (FLAC) (DEPRECATED)

The display name says it all: "Save Audio (FLAC) (DEPRECATED)". This node saves your AUDIO tensor as a lossless FLAC file in ComfyUI's output directory, and it does that job perfectly well. The word "deprecated" isn't a warning that it's broken - it's a notice that it's been replaced by a single node that does everything this one does and more.

It's one of the three original save nodes from ComfyUI's audio rollout (mid-2024, same era as Stable Audio Open support), when FLAC was the one lossless format the pipeline could write natively. It held the fort for a long time. Then MP3 and Opus savers joined it in mid-2025, and in June 2026 ComfyUI consolidated the whole trio into SaveAudioAdvanced. The three old savers are kept around so old workflows don't break, but they're now just wrappers around the same save helper.

What it does

It's a terminal node: feed it an AUDIO tensor, and it writes a .flac file to your output/ directory using the filename_prefix as the path prefix. The default prefix, audio/ComfyUI, means the file lands in output/audio/ with a name like ComfyUI_00001_.flac - the save helper appends a counter so you never overwrite an earlier run. Put a different folder in the prefix, like music/final, and it creates that subfolder for you.

Lossless FLAC means zero quality loss, but big files. If you're archiving a master or feeding a video muxer, FLAC is the right call. If you just need something to email or upload, you want MP3 or Opus - which this node can't do.

Inputs and output

• audio (AUDIO) - the track to save.
• filename_prefix (STRING, default audio/ComfyUI) - output path prefix; subfolders are created automatically.
• audio (AUDIO, output) - passthrough of the saved track, added to save nodes in 2026 for uniformity. You don't need to connect it.

Getting it

Ships with ComfyUI core. If your install is from before June 2024 it won't be there - update, because the whole audio category is core now.

The catch

The one error this node throws is worth knowing before it bites you: "input audio is None (source video may have no audio track)". Feed it a silent video's track and it won't gracefully write silence - it raises. Check your source has audio before saving.

And honestly: just use SaveAudioAdvanced for new workflows. It does FLAC, MP3, and Opus from one node, with the same filename_prefix behavior. SaveAudio still works, but it's a legacy path and the DEPRECATED label is ComfyUI telling you which way the project is moving.