Multi Noise

Sometimes the problem isn't "how do I generate this" - it's "how do I jitter it." Multi Noise adds random Gaussian noise to images, latents, or masks, scaled by a strength you set. It's a tiny utility node, but it quietly unlocks a bunch of tricks: adding noise before an img2img pass, perturbing latents to explore variations, or degrading a mask to make an inpainting pass more robust.

What it is

One of the pack's "Multi" nodes - it does the same operation across images, latents, and masks in a single node, rather than making you hunt down three separate nodes. Inputs: strength (0–10, default 0.1) and a color toggle. Outputs: the same three tensor types, with noise added.

The two knobs, explained

• strength - the standard deviation of the Gaussian noise. 0.1 is subtle (just enough to break up banding), 1.0 is "loud," and beyond that you're basically destroying the input. It's additive: the output is input + randn * strength, with no clamping, so values can drift outside the normal range - keep that in mind if you're feeding the result somewhere picky.
• color - whether the noise is per-channel or shared. false (default) adds the same noise pattern to all channels, which is grayscale noise - it shifts brightness without shifting hue. true adds independent noise per RGB channel, which produces the color-speckle you sometimes want for creative jitter.

Why you'd actually use it

• Img2img variation. Drop a bit of noise on a latent before a sampler pass and you nudge the result without changing the seed. Low strength = "same image, slightly different"; higher = exploring more.
• Robustness testing. Adding noise to a mask before an inpainting or compositing step makes your workflow less brittle - the effect is a more forgiving edge. Some people do this deliberately to make masks less surgical.
• Degrading input. Simulating noise on a source image to see how a restorer handles it. It's a crude sim, but it's one node.

Honestly, for most users this node is a "when you need it, you need it" utility - you'll go weeks without touching it, then want exactly one node that adds controlled noise to three tensor types at once and reach for it.

The gotcha

It only acts on whatever is connected. If you wire only images, the latents and masks outputs pass through untouched - no noise applied, no error, no warning. That's consistent with the whole Multi family (unconnected inputs pass through), but it's the most common "why didn't it work" moment with this node. Check your wires.

Install

Part of Zuellni/ComfyUI-Custom-Nodes, via ComfyUI Manager (search "Zuellni") or:

cd ComfyUI/custom_nodes
git clone https://github.com/Zuellni/ComfyUI-Custom-Nodes

No extra requirements, no downloads - it's pure torch. The pack is archived, but this node is stable, dependency-free code that will keep working. If you need per-tensor noise with clamping or a seed control, you'd want a more featureful pack (WAS Node Suite has the kitchen sink); if you need exactly this, this is exactly this.