Fast Image Preview

Every ComfyUI graph ends in a wall of preview nodes, and the stock Preview Image node is fine right up until you feed it a big batch - a hundred video frames, say - and the UI chugs while it writes out and renders every single one as a full PNG. Fast Image Preview exists to fix exactly that annoyance: it shows you a thumbnail first, then loads a full-resolution WebP version in behind it, instead of dumping raw PNGs at you all at once. Same job, noticeably less waiting when you're iterating on anything with more than a few frames.

How it works

You wire in a batch of images and it renders them right there on the node - thumbnail fast, full-res a beat later. That's the whole trick: it front-loads something cheap to look at so you're not staring at a spinner while ComfyUI serializes a hundred PNGs, and WebP compresses better than PNG for photographic content anyway, so the full-res load is lighter too.

The inputs and outputs that matter

There's exactly one input and it's the only thing you need to think about:

• images (IMAGE, required) - your batch. Connect the output of whatever generated or processed your frames and you're done; there's nothing else to configure.

There are no outputs. This is a terminal node - it displays, it doesn't pass anything downstream. If you need the same images somewhere else in your graph, branch the wire before it hits Fast Image Preview, not after; there's nothing to grab off this node once it's plugged in. It's also flagged as an output node internally, which means ComfyUI will always execute it if it's in the graph, even if literally nothing else depends on it - handy to know if you're ever confused why a branch runs at all.

How to install it

Easiest path is ComfyUI Manager: open it, search for "Link Comfy Nodes," install, restart. Manual route, if you'd rather:

cd ComfyUI/custom_nodes
git clone https://github.com/Mister-Link/link-comfy-nodes
pip install -r link-comfy-nodes/requirements.txt

Restart ComfyUI afterward. The pack is a grab-bag of video, image, color, and workflow utility nodes - Fast Image Preview is one small piece of it, so don't expect a dedicated model download or anything heavy; it's a UI node, not a generator.

Common issues & troubleshooting

Nothing downstream, and that's expected. The most common trip-up with this node is treating it like a passthrough - trying to chain something off its output and finding there isn't one. It's a dead end by design; that's what makes it fast.

Missing the node after install. If it doesn't show up after a Manager install or manual clone, make sure you actually restarted ComfyUI rather than just refreshing the browser tab - custom node packs only get scanned and imported at server startup. If it's still missing, check the console log on launch for an import error from link-comfy-nodes; that almost always means the pip install -r requirements.txt step got skipped, since this is a multi-node pack with its own dependency list, not a zero-dependency single-file node.

Still slow on very large batches. WebP and thumbnailing help a lot, but a genuinely huge batch (hundreds of frames) is still a lot of image data for the browser to hold and render. If you're previewing that much, consider whether you actually need to see every frame, or whether a spot-check on a subset would do - that's a workflow problem the node itself can't solve for you.