Seed Shifter

If you've ever run a batch of images and then been unable to recreate the one good result, you know the pain Seed Shifter exists to solve. It takes a base seed and turns it into a predictable list of seeds - same inputs, same list, every time. Which is precisely what you want when you're generating a grid of variations and need each cell to be reproducible.

Here's the whole mechanism: seeds = seed + seed_shifter + i for i from 0 up to batch - 1. That's it. The seed_shifter value is a fixed offset that moves the whole sequence, and the batch index walks it forward one at a time. Because it's pure arithmetic, there's no randomness anywhere - which is the entire point. You can regenerate the same five seeds tomorrow, next week, or on someone else's machine, and get the same sequence.

Inputs and outputs

Three inputs, one output:

• seed - your base seed. Wire it from a normal seed node or just type one.
• seed_shifter - the offset, default 0. Bump it to shift the whole batch - the classic trick for "same prompts, new pass, don't repeat last time's exact results."
• batch - how many seeds to generate, default 1.
• seeds - the generated list of INTs. Feed it to a KSampler seed input, or into a batch/loop context, and each step pulls the next seed from the list.

Why you'd bother

ComfyUI already has seed controls, so is this redundant? Mostly yes, until it isn't. Where this earns its keep is in controlled iteration - running the same tiled upscale or img2img chain across several seeds and wanting the mapping of "seed number → result" to stay stable and inspectable, or stepping a grid of denoise strengths at the same seed to isolate what the setting actually did. And because the output is a plain list, you can also record it, store it, and replay it. If you only ever batch through the built-in seed widget, you don't need this node. The moment you want a reproducible sequence outside of ComfyUI's own batch handling, it's exactly the right size.

Install

It's part of the ComfyUI Steudio pack, in the Utils menu:

cd ComfyUI/custom_nodes
git clone https://github.com/Steudio/ComfyUI_Steudio

Restart ComfyUI, or install via ComfyUI Manager by searching ComfyUI Steudio. No dependencies, nothing to download. Just remember the arithmetic is deterministic - if you change seed_shifter or batch, you get a different list, and that's the feature, not a bug.