HiDream I1 Fast is a lightweight text-to-image workflow tuned for rapid previews and low-VRAM GPUs. It pairs the HiDream I1 Fast FP8 UNet (loaded with UNETLoader) with SD3-style sampling (ModelSamplingSD3) and runs just 16 inference steps in KSampler. Prompts are handled through QuadrupleCLIPLoader and CLIPTextEncode, while EmptySD3LatentImage creates the starting latent at your chosen resolution. The result is a fast, responsive pipeline that’s ideal for exploring ideas and iterating on compositions without long waits.
Technically, the workflow loads a matching VAE via VAELoader and decodes samples with VAEDecode, then writes outputs using SaveImage. ModelSamplingSD3 exposes the HiDream/SD3 “shift” parameter (commonly around 3.0 per official guidance) to balance prompt conditioning across multiple text encoders. Because the UNet is FP8 and the step count is low, VRAM use stays modest, making this a practical option for laptops or older GPUs while still producing coherent, stylized results.
API
Use this workflow from code
Every Comfy workflow is a JSON graph. The payload below is this workflow, exactly as ComfyUI runs it — fetch it from the URL, keep it in version control, or load it in ComfyUI and run it node by node.
Run it from TypeScript or Python with the Comfy SDK. The same code targets Comfy Cloud or a ComfyUI you host yourself — only the base URL changes.
// Install (beta)
npm i @comfyorg/sdk
// Run "HiDream I1 Fast" (TypeScript)
import { Comfy } from "@comfyorg/sdk";
const client = new Comfy({ apiKey: "comfyui-..." });
// This workflow, exported in API format (see note below)
const wf = await client.workflows.fromFile("hidream_i1_fast_api.json");
wf.setInput("85", "text", "your prompt here"); // CLIPTextEncode
const job = await client.run(wf);
await job.getOutputs("88")[0].toFile("output.png"); // SaveImageThe SDK takes a workflow in API format: open this workflow in ComfyUI and use File → Export Workflow (API).
Comfy Cloud API access requires a plan with an API key.
FAQ
