DD Model Switcher

DD Model Switcher is the checkpoint version of the switcher family: up to four MODEL inputs in, one MODEL out, chosen with an integer. It doesn't load anything itself - you still use your normal loader nodes and wire their outputs here. What it saves you is the rewiring.

Why you'd use it

The big one is checkpoint A/B testing. Two checkpoints loaded side by side (maybe an SDXL base and a photoreal merge, or a base and a distilled fast version), both wired into this node, and one 选择输出 (Select Output) number picks which one the KSampler actually samples with. You queue the same workflow with a different number and you've got a clean comparison - same prompt, same seed, same steps, only the model changes. That's the most honest way to compare checkpoints, because you haven't touched anything else while swapping.

It's also how you keep one "canonical" workflow that you reuse with different models. Keep both loaders in the graph, set the selector, and the workflow reads as one artifact instead of two near-identical copies. Given how much of ComfyUI's culture is sharing workflows as files, a switch like this makes the shared graph smaller and clearer.

How it works

Plain list-and-index, same as the rest of the series. Model 1 and Model 2 are required; Model 3 and Model 4 are optional. The selected model comes out of the single 模型 (Model) output and goes wherever a MODEL normally goes - into a KSampler, a LoRA stack, whatever. One behavior worth knowing from the source: pick slot 3 or 4 with nothing wired in and it warns and falls back to Model 1 instead of failing. Fine, but it's a footgun - a "3" in the dropdown with no wire on port 3 means you're silently sampling with Model 1. Verify the port you selected is actually connected.

Installation

Same one-pack install as everything else in DD-Nodes:

cd ComfyUI/custom_nodes
git clone https://github.com/Dontdrunk/ComfyUI-DD-Nodes
cd ComfyUI-DD-Nodes && pip install -r requirements.txt

Restart ComfyUI, or grab it through ComfyUI Manager by searching "ComfyUI-DD-Nodes". No model files are downloaded by the pack itself - the checkpoints you switch between are the ones you already have in your models folder.

Honest take

Is this node necessary? No - you can rewire by hand. But once your workflows get past a couple of dozen nodes, every wire you don't have to drag is a small gift. It's a shallow utility, it doesn't overreach, and it's already in the pack if you run DD-Nodes for anything else. The one real complaint: it's manual only. There's no input to drive the selection from another node, so it's a knob you turn between queues, not something an automation can drive. For that you'd want a more sophisticated router - but for daily "try the other model" work, this is the right tool. Also note the pack's UI is Chinese-first; flip the language in ComfyUI settings if you want English labels.