h4 - Universal Loader (Retired)

Straight answer first: H4_UniversalLoader is marked Retired and lives in the pack's _Legacy category. The display name says it, the category says it, and the pack's own index calls it "Skeleton Key" while pointing you at H4_CompleteLoader as the current all-in-one. If you're installing h4_Live fresh in 2026, you don't need to use this node - but you'll see it, you might inherit a workflow that uses it, and knowing what it was doing makes both situations painless.

What it was: a single loader that could stand in for CheckpointLoaderSimple + UNETLoader + VAELoader + CLIPLoader + LoraLoader. Feed it a checkpoint, or a standalone UNet/VAE/CLIP with an optional LoRA, and it hands you a ready MODEL, CLIP, and VAE - three sockets, one node.

How it works

It has two load_mode options:

• Checkpoint (Standard) - the usual path. Pick a checkpoint from ckpt_name, and it loads model + CLIP + VAE from that single file (using ComfyUI's standard config-guessing loader). If you set a LoRA, it applies it at lora_strength before handing anything out.
• Diffusers (Component) - the more advanced mode. Instead of a checkpoint you pick a standalone unet_name, plus optional vae_name and clip_name (each with a Baked / None option). Notably, the UNet list includes .gguf files, and if the filename ends in .gguf the loader delegates to ComfyUI-GGUF for quantized model loading - so it could load a GGUF-quantized UNet in the same node, no separate GGUF loader node needed. The clip_name list picks up .gguf CLIPs the same way.

There's also a thoughtful safety check baked into the checkpoint path: it detects Lumina/Z-Image-style models (which expect 2560-dim Gemma embeddings) paired with a T5/XXL clip (4096-dim) and prints a loud warning explaining exactly which text encoder you need instead, so you don't hit a cryptic normalized_shape crash mid-sampling.

Outputs: MODEL, CLIP, VAE.

Installing h4_Live

Part of the h4_Live pack. ComfyUI Manager: search h4_Live, install, restart. Or:

cd ComfyUI/custom_nodes
git clone https://github.com/m3rr/h4_Live

Restart. No model files required by the pack itself. For .gguf support specifically, you do need ComfyUI-GGUF installed (that's a separate pack via Manager) - the loader only delegates to it when it's present.

Common issues

• It's retired. For new workflows, use H4_CompleteLoader (same pack) or just stock loaders. The UniversalLoader is kept around so old workflows keep loading - if you open a shared workflow that uses it, it'll still work.
• GGUF requires ComfyUI-GGUF. The .gguf options appear in the dropdowns only when the GGUF pack has registered its folders. No GGUF pack, no GGUF options - the loader degrades gracefully to standard models.
• Diffusers mode demands a UNet. Pick Diffusers (Component) with no unet_name and it raises a clear "No 'unet_name' selected!" - that's expected, not a crash.
• Zero dependencies. The pack's manifest declares no pip requirements at all; everything it calls is ComfyUI stock. That's genuinely nice for a pack this size - no install-order hair-pulling.
• Honest scope note. This is a young, single-developer pack with essentially no community footprint yet, and this is the pack's own legacy corner. Don't treat it as a battle-tested standard; treat it as "the author's opinionated loader" and you'll know what you're in for.