Seed Selector

A tiny quality-of-life node that solves a real annoyance: you're iterating on a prompt and want to lock the seed so you're comparing apples to apples, then you nail it and want to randomize again to explore variations. Normally that means fiddling with the KSampler's control-after-generate setting or swapping wires. SeedSelector puts a switch on it - one toggle picks whether the workflow uses a random seed or a fixed one you typed in, and it outputs that seed as an INT you feed to the sampler.

It's the kind of node you don't think about until you're deep in an iteration loop and realize you keep accidentally changing the seed when you meant to hold it (or holding it when you meant to explore). Wire this once and the toggle handles it.

How it works

It holds two seed values - a seed and a fixed_seed - and the mode boolean chooses which one flows to the output. So you keep a known-good seed parked in fixed_seed, let seed do the randomizing, and flip mode to switch between "lock to my saved seed" and "use the varying one" without touching anything else in the graph.

The inputs and outputs that matter

• mode - the switch (boolean, default true). It selects which of the two seeds gets output. Since there's no universal "true = which," just toggle it once and watch the output seed to learn which state is which in your build - then leave it set to what you want.
• seed - a seed value, 0 up to the full 64-bit range (~1.8×10¹⁹, the standard ComfyUI seed ceiling). This is the one you'd let randomize.
• fixed_seed - the seed you want to keep, same range. Park your golden seed here so it survives while you experiment on the other path.

Output is a single seed (INT). Wire it into your KSampler's seed input.

How to install it

Part of the Art Venture pack. ComfyUI Manager → search comfyui-art-venture → Install → restart. Manually:

cd ComfyUI/custom_nodes
git clone https://github.com/sipherxyz/comfyui-art-venture

then pip install -r comfyui-art-venture/requirements.txt and restart. No model download.

Common issues & troubleshooting

My seed keeps changing when I wanted it fixed (or vice versa). That's the mode toggle in the state opposite to what you assumed. There's no standard for which boolean value means "fixed," so set it, run twice, and confirm the output seed stays put (fixed) or moves (random). Two seconds, and you'll never second-guess it again.

The seed isn't actually randomizing. Remember ComfyUI's own "control after generate" on the sampler still exists. If you're routing a seed through this node, make sure you're not also fighting the sampler's built-in increment/randomize behavior - drive the sampler from this output and let the node own the decision.

Do I even need this? If your seed logic is simple, the KSampler's native controls may be enough. SeedSelector earns its slot when you want an explicit, visible switch between a saved seed and a fresh one - particularly in workflows you hand to other people, where a labeled toggle beats "remember to set control-after-generate to fixed."

Node missing after a workflow import. The pack isn't installed - Manager → Install Missing Custom Nodes.