NIX_SaveImage

NIX_SaveImage is a replacement for the stock Save Image node, with one genuinely useful twist: it lets you choose, per run, whether the output is a PNG with your full workflow embedded or a clean JPEG with no metadata at all. That's the whole personality of this node, and if you've ever shipped an image to a client or a forum and wanted the workflow off it, you know why that toggle matters.

It's part of the NIX pack - small, no models, dependencies are just numpy and Pillow (both already in ComfyUI). Install once, get a dozen utilities including this.

How it works

• images (required) - the batch to save. Each image in the batch gets its own file.
• filename_prefix (required) - the base name. It's sanitized (path separators and junk characters become underscores), and if you accidentally include an extension it's stripped - you don't control the extension here, the format toggle does.
• output_path (optional) - a custom folder. Empty means the standard ComfyUI output directory.
• image_format - and here's the trick: it's a boolean, not a text dropdown, with the labels doing the talking. Toggle on = png; toggle off = jpg.

When the toggle is on (PNG), the node embeds the workflow as PNG metadata - the prompt and extra_pnginfo - exactly like the stock Save Image, so dragging the image back into ComfyUI reconstructs your graph. When it's off (JPG), it saves a quality-100, no-chroma-subsampling JPEG with no metadata, which is smaller and shareable but workflow-less.

Filenames never overwrite: if my_image.png exists, it writes my_image_2.png, and so on.

This is an output node - it has no image output to wire onward; it's the end of the line. It does produce a UI preview (filenames) if you're using the default output directory.

When you'd use it

• Shareable JPEGs without workflow baggage - the toggle-off mode. Handy for client work or anywhere you don't want your graph embedded.
• Custom output folders - point output_path at a project directory and stop fishing through the default output folder.
• Metadata-preserving PNGs when you want them - toggle on behaves like the node you already know.

Getting it installed

• ComfyUI Manager: search "NIX" / "NIX ComfyUI Plugin", or Install Custom Nodes → Git URL → https://github.com/J-ChenX/ComfyUI-NIX. Restart after.
• By hand:

  cd ComfyUI/custom_nodes
  git clone https://github.com/J-ChenX/ComfyUI-NIX
  

  Restart ComfyUI. Under the "NIX" category.

Things that will bite you

• image_format is a toggle, and the label flips. It reads "png" when on and "jpg" when off. Get it backwards once and you'll be shipping metadata when you meant clean JPEGs - check the label before you queue.
• Custom output_path disables the preview. The node still saves; it just doesn't report filenames to the UI. Not a bug, just quiet.
• JPEG quality is locked at 100. Great for quality, bad for file size - a quality-100 JPEG can be nearly as big as a PNG. If you want small JPEGs, this isn't the node.
• Batch = one file per image. A 10-image batch writes 10 files, auto-numbered.
• Quiet pack. No community signal for NIX as of mid-2026, so no crowd-tested recipes - but the save logic is simple and readable in the source if you want to confirm the metadata behavior.