Preview Video MXD

A video preview that doesn't commit. If you're iterating on a Wan 2.2 or LTX generation and you don't want every test render landing in your output folder as a numbered mp4, this is the terminal node to drop at the end of your graph - preview the clip, decide, and only attach a real saver when you're happy.

Preview Video MXD is one of the small quality-of-life nodes in Maxed Out's pack, and it exists because video generation has a specific waste problem: a single test clip can be a couple of GB of encode time and a file you never look at again. The description on the node is refreshingly blunt - "preview a video without saving output (optional pass-through)." That's the whole job.

How it works

It takes a VIDEO-type input - the newer ComfyUI video format that the Wan/LTX video pipelines produce - and shows it in the viewer. No file gets written to disk. What makes it slightly cleverer than a plain preview is the pass-through: it also outputs output_video, which is the same video handed forward ("passes the same video forward", per the tooltip), so you can fork the preview into a saver later without rewiring the graph. Preview to look, and pass through to keep your options open.

Inputs and outputs

• input_video - the VIDEO to preview.
• output_video - pass-through of the same video, so downstream nodes can still grab it.

It's marked as an output node, so it terminates the graph - you don't need to hang a saver off it unless you want the file.

Installing it

Ships in the ComfyUI-MaxedOut pack. ComfyUI Manager search Maxed Out, or:

cd ComfyUI\custom_nodes
git clone https://github.com/Maxed-Out-99/ComfyUI-MaxedOut.git

Restart ComfyUI. No extra dependencies, no models to fetch.

The honest note

This node only makes sense if your pipeline already speaks the VIDEO type - if you're working frame-by-frame with an IMAGE batch, you'll be feeding it through a converter first. And since it writes nothing, it's a preview node, not a backup: the moment you close ComfyUI, the clip it showed is gone unless you saved it elsewhere. Use it for iteration, not for keeping.