Lora Loader 🐍

This does the same job as ComfyUI's stock LoRA loader - it patches your checkpoint's MODEL and CLIP with a LoRA's weights, altering how latents get denoised so you can apply a style, character, or concept on top of a base checkpoint. What's different is entirely quality-of-life: instead of a bare dropdown of filenames, you get preview thumbnails, saved example/trigger-word prompts, and a proper info panel, all wired into the same picker.

It's from ComfyUI-Custom-Scripts, a big utility pack by pythongosssss - worth knowing that name isn't a random hobbyist, he co-founded Comfy Org in June 2024 alongside comfyanonymous and the ComfyUI-Manager author when the project split from Stability AI.

What a LoRA is doing here

A LoRA is a small adapter - 10 to 200 MB, versus multi-gigabyte checkpoints - that nudges a checkpoint's cross-attention layers rather than replacing anything. That's why you need a base MODEL and CLIP already loaded before this node has anything to work on: a LoRA can't generate on its own, it only modifies. Multiple LoRA nodes chain fine - MODEL/CLIP out of one straight into the next - the standard way to stack a style LoRA with a character LoRA with a detail LoRA in one graph.

The inputs and outputs that matter

model and clip are required - wire them straight off your checkpoint loader. lora_name is a dropdown built from your models/loras folder. strength_model and strength_clip both default to 1.0 (the node technically allows -100 to 100, but nobody sane goes much past 1.5). There's also an optional prompt text input, which mostly matters for scripted or automated setups rather than everyday manual use.

Outputs: MODEL and CLIP go onward exactly like the stock loader. There's a third output, example - a snippet of saved sample prompt or trigger-word text, if the LoRA has one. That's tied to a specific file convention: drop a folder of .txt files next to the LoRA, named to match it (e.g. loras/add_detail/*.txt for loras/add_detail.safetensors), and this node surfaces that content. Not every LoRA has one; it's opt-in, something you build up yourself over time.

The preview-image trick

Drop a .png or .jpg with the same base filename next to your LoRA (sdxl.safetensors + sdxl.png) and it shows on hover in the picker - genuinely useful once you've got a few hundred LoRAs and can't remember which is which from the filename alone. Right-click any output image in ComfyUI and choose "Save as Preview" to generate one directly from a result you just got, instead of hunting one down separately. There's also a "View Info" menu option for checking a LoRA's metadata without leaving the app.

Strength, ordering, and compatibility - the things that actually go wrong

A few grounded rules of thumb worth internalizing before you fight with a LoRA that "isn't working":

• Default 1.0 is often too strong. 0.5–0.8 is a more common practical starting point, especially stacking multiple LoRAs at once.
• Order matters when stacking. The general community advice is to put the LoRA with the larger effect earlier in the chain and subtler ones later.
• Base model compatibility is not optional. A Flux LoRA plugged into an SDXL MODEL socket won't work, and Pony/Illustrious/SDXL LoRAs, despite sharing an architecture family, are often not cross-compatible even though the dropdown lets you select them.
• Missing trigger words are the single most common "LoRA does nothing" cause. Check the example output or the model's source page - many LoRAs need a specific word in the prompt to activate at all.

Stacking three or more with per-entry toggles? rgthree-comfy's Power Lora Loader is the newer alternative built for exactly that. This node stays the simpler, one-LoRA-per-node option - cleaner for a one- or two-LoRA graph.

Installing it

• ComfyUI Manager - search "ComfyUI-Custom-Scripts", install, restart.
• Manual - cd ComfyUI/custom_nodes && git clone https://github.com/pythongosssss/ComfyUI-Custom-Scripts, restart.

No models ship with the pack - you supply your own LoRA files in models/loras.

Common issues & troubleshooting

Dropdown is empty. Nothing in models/loras, or ComfyUI hasn't picked up a file you added since the last start - restart or refresh.

No thumbnail on hover. The preview image needs the exact same base filename as the LoRA and needs to sit in the same folder. A mismatched name, even by a character, means no preview, silently.

No example/trigger text in the example output. That needs the matching sidecar .txt folder described above. It's opt-in per LoRA - plenty of files simply don't have one.

LoRA seems to do nothing. Check strength first (too low, or you forgot the trigger word), then architecture compatibility (wrong base model family). Those two cover the overwhelming majority of "it's not working" reports. If you're on an anime checkpoint (Illustrious/Pony/NoobAI-lineage), also check whether CLIP skip needs to be set - many of those LoRAs expect CLIP skip 2.