RedNode Video Review

Every video workflow - LTX, Wan, Hunyuan, pick your poison - ends the same way: a stack of frames comes out the sampler and stock ComfyUI shows you a still, or nothing, until you save the video and open it in a player. RedNode Video Review is the preview node that closes that loop. It plays the clip right in the node, with a scrubber, with sound if you fed it audio, and - the part that sells it - it keeps the last few runs in a strip below, so the previous attempt is still there to compare against instead of vanishing into the next queue.

That "it remembers" bit is the quiet killer feature. In stock ComfyUI, once you queue another run the old output is gone; if you didn't save it, you're comparing from memory. This node treats video preview the way RedNode Image Review treats stills: browse the last few runs, scrub through, judge whether attempt three actually fixed attempt two's wobble.

How it works

RedNode Video Review is an output node with no outputs - this is where frames end, so it sits at the tail of the graph. There are two ways in, and they're exclusive:

• Wire images - the batch of frames in order. The node encodes them to a preview clip and drops it in ComfyUI's temp folder. Nothing is filed to your output directory, so this is the node you leave wired while you iterate; it can't pollute your save tree.
• Wire video_path - the path output of the pack's RedNode Save Video. This plays the file that was actually written: no second encode, real quality, real container. When both are connected, the path wins.

The remaining inputs are the controls you'd expect: fps (default 16, range 0.1–240 - wire it from whatever made the frames and the preview plays at the real rate; it's ignored when a video path is wired, since the file carries its own), audio for sound to play along, and loop (default on - short clips are easier to judge looping).

Why you'd reach for it

Honestly: iteration. Video is slow to generate, and the whole game is catching problems early - a flicker, a morphing face, a jump cut - before you've burned a full multi-minute render. A preview that plays instantly in the node, remembers the last few attempts, and never writes junk to your output folder is exactly the tool for that. And because it plays in the node rather than dumping you out of the graph, you stay in the flow: spot the problem, tweak the seed or the denoise, queue again, compare in the strip.

Installing it

It ships in RedNode Studio, the same pack as the Switch and Text Combine nodes - 52 nodes, no pip dependencies. ComfyUI Manager → search "RedNode Studio", or:

cd ComfyUI/custom_nodes
git clone https://github.com/RedNodeAI/ComfyUI-RedNodeStudio.git

Restart, and it's under the RedNode category in the node menu. Python 3.10+; no model downloads for this node specifically. Pack license is PolyForm Noncommercial - fine for personal/hobby work, commercial use needs the author's permission. One housekeeping note: the depth of that "previous runs" strip is configurable under Settings > RedNode ("how many runs the Review strip keeps"), so if it's hoarding more than you want, trim it there.

Common issues

• No sound and the preview looks like a flipbook - you're on the frames path without audio wired, and possibly at a low fps. Wire audio in and drive fps from whatever produced the frames.
• A preview that won't play at all - if ffmpeg isn't available, the node falls back to an animated webp. That's silent, but it still plays, and it's the floor. Audio needs the real encoder.
• The video_path is wired but you get the frames anyway - the path was stale or unreadable; the node logs "nothing playable at …" and falls back rather than failing. Re-run the save node so the path points at a file that exists.

For the price of one node at the end of your video graph, you stop squinting at a single frame and start actually watching what you made. That's worth the install by itself.