🌊📺 FlowState Video Preview

This is a three-line node whose entire existence is an indictment of ComfyUI's video workflow. Its description - written by the author himself - is literally "simple preview video node. Don't know why this isn't a node." He's right: as of the current core, taking a VIDEO and showing it in the browser without also committing it to disk is awkward enough that people ship custom nodes for it. FlowState Video Preview is that node.

What it does

It takes one input, video (VIDEO), writes the clip to a temporary video file, and shows it in ComfyUI's preview area so you can actually watch what your sampler produced. It's an output node with no sockets out, and it doesn't clutter your output/ folder the way a save node does - the temp file is meant for preview, not archival. In a FlowState video graph, it's the "check the take before committing to a file" node: wire WAN Studio's video output here while you iterate, and swap to FlowState_VideoCreator when you're ready to save something for real.

The one input

Just video (VIDEO). That's it. No fps, no format, no filename - the node doesn't care about any of that because it isn't producing an artifact. If you're coming from the image world, think of it as the video equivalent of previewing an image: it exists so you don't have to save to look.

Why you'd bother

Two use cases. The first is iteration: every run of a save node writes a file, and files pile up fast when you're tweaking a prompt or a seed. Preview lets you watch infinite takes without building an archive you didn't ask for. The second is that it decouples "look at the result" from "keep the result" in a graph - which matters when you're chaining a second pass or an upscale, because you can preview the intermediate video without dumping it to disk. It's also the only node in the suite's video trio that takes a VIDEO rather than a frames IMAGE, so it slots in at the end of other packs' video outputs too.

Install

Part of the FlowState Creator Suite:

cd ComfyUI/custom_nodes
git clone https://github.com/flowstateeng/FlowState-Creator-Nodes

then restart, or install FlowState-Creator-Nodes via ComfyUI Manager. No dependencies, no model files - it wraps a temp-file writer over the video type ComfyUI already uses internally.

Honest notes

It's the thinnest node in the pack and shouldn't be overthought - the whole value is "VIDEO goes in, video plays in the UI." The catch is that video previews in ComfyUI have always been slightly environment-dependent: on some setups you need to look at the output panel rather than the node's own preview, and very long clips may not scrub smoothly in the browser. If that happens, it's ComfyUI's frontend, not this node. And if you actually want the file, this isn't the node - that's what FlowState_VideoCreator is for. Preview and save are two different jobs, and the suite splits them on purpose.