🪛 Preview from metadata

Crystools ships two "preview and inspect" nodes that look similar but answer different questions, and the distinction is the whole reason this one exists. Preview from image takes a live image link and shows you the current prompt - but under the hood it has to save a temp copy to show anything, so what you're actually looking at is the temp file's data, not necessarily what's really baked into the source. Preview from metadata skips the live image entirely and works straight from a metadata record, so what it shows you is the real, already-saved data - the actual prompt, workflow, and file info as they exist on disk, not whatever the upstream nodes currently say.

That matters more than it sounds like. If you've been tweaking a workflow and want to check "wait, what did I actually run to get this specific saved image," Preview from image will show you the live current state of your graph, which may have already drifted from what produced the file. Preview from metadata shows you the file's own record instead.

How it works

It reads a METADATA_RAW blob - the same custom type produced by Load image with metadata, Preview from image, or Save image with extra metadata - and reconstructs the preview and its associated data from that record. Like its sibling, it supports the pack's caching behavior, so you can disconnect the input and still see what was last shown.

The inputs and outputs that matter

• metadata_raw - optional input, METADATA_RAW type. Feed it the Metadata RAW output from Load image with metadata (or any other Crystools node that produces that type).
• Output: Metadata RAW - the same metadata passed back through, so you can keep chaining it - into Metadata comparator to diff it against another image's record, for instance.

This is an output node, meaning it displays directly in the UI even without anything wired downstream - that's the point, it's a viewer.

How to install it

Through ComfyUI Manager: search crystools, install, restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/crystian/comfyui-crystools.git
cd comfyui-crystools
pip install -r requirements.txt

Restart and find it under crystools 🪛 / Image. No model downloads - this is a viewer node, not a generator.

Common issues & troubleshooting

The input is optional in the schema, but functionally the node has nothing to show without a METADATA_RAW value feeding it - so if it renders empty, check that you've actually wired in a Metadata RAW output from one of the pack's other image nodes rather than trying to connect a plain image link (that's what Preview from image is for, and the two aren't interchangeable).

The pack's README also flags that caching isn't permanent yet - it survives disconnecting the node mid-session, but not a page refresh or a server restart, so don't rely on it to preserve a comparison across a restart. And if you're chasing "why does this show different data than I expected," remember the core distinction above: this node trusts the metadata record over the live graph, which is exactly what you want when auditing a saved output, and exactly what'll confuse you if you were expecting it to reflect changes you just made upstream.