FL Save WebP Image

PNG is lossless and honest and also enormous. If you're churning out hundreds of test images or building a gallery, those files add up fast, and most of that fidelity is invisible. FL_SaveWebPImage saves your output as WebP instead - a modern format that's dramatically smaller than PNG at quality you won't notice on a screen - and hands you back the file path as a string so downstream nodes can do something with it.

WebP is the sweet spot for "I want this small but still good." A WebP at quality 80 is a fraction of the PNG's size and looks the same in a browser. For anything web-bound, or any workflow where you're keeping a lot of images, it's the format that stops your disk filling up. This node is just the ComfyUI-friendly way to write one.

The inputs and outputs

Three inputs, and only one is a real decision:

• images (IMAGE) - the batch to save.
• filename_prefix (default ComfyUI) - the name stub; it writes into your ComfyUI output directory with the usual auto-numbering.
• quality (1–100, default 80) - the WebP quality. 80 is a great default; go to 90–95 if you're precious about it, drop toward 60 if you want tiny thumbnails and don't mind soft edges. Lower means smaller and lossier.

Two outputs:

• images (IMAGE) - passthrough, so you can keep chaining after the save.
• STRING - the saved file's path. This is the handy bit: wire it into a node that needs to know where the file went - an uploader, a Discord webhook, a caption saver, anything that acts on a path rather than a tensor.

Installing it

It's part of ComfyUI_Fill-Nodes. In ComfyUI Manager, search Fill-Nodes, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/filliptm/ComfyUI_Fill-Nodes

then restart ComfyUI. No model download; saving WebP is handled by the imaging libraries the pack already installs.

Worth knowing

WebP is lossy at anything under quality 100, so it is not the format to use for images you'll re-edit, re-sample, or upscale later - each save-and-reload throws away a little more. Use it for final outputs and shareables, keep PNG (or the pack's FL_SaveRGBAAnimatedWebP for transparent animations) for masters you'll come back to. Also note: standard WebP here is your still-image save; if you need transparency preserved, check whether your quality setting is high enough, because aggressive compression eats fine alpha edges. For the common case - "save my finished picture small" - set quality 80, wire the STRING output wherever your path needs to go, done.