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Gemini 4 Hydrogen is one of the Gemini 4 text models available in the Google Gemini partner node. You attach a reference image and a text instruction, and the model writes the text you asked for: an art-directed prompt, a detailed caption, or a structured breakdown of what the image contains. It returns plain text, so the result can feed another node in the same workflow instead of ending in a chat window.

What Gemini 4 Hydrogen is good at

  • Reverse-engineering prompts: Turn an image into a reusable positive prompt that covers subject, composition, camera, lighting, palette, texture and style
  • Detailed captions: Write long descriptive copy for a still frame, with the reasoning depth to keep the description coherent across paragraphs
  • Structured visual analysis: Ask for an element-by-element breakdown of a layout, chart or scene instead of a single paragraph
  • Multimodal context: Besides the image, the node accepts an audio clip, a video clip and files through Gemini Input Files, up to 16 images in total
  • Batch annotation: Run a folder of images through the workflow with a Save Text node so every result lands as a file
To use the Partner Nodes, you need to ensure that you are logged in properly and using a permitted network environment. Please refer to the Partner Nodes Overview section of the documentation to understand the specific requirements for using the Partner Nodes.
Make sure your ComfyUI is updated.Workflows in this guide can be found in the Workflow Templates. If you can’t find them in the template, your ComfyUI may be outdated.If nodes are missing when loading a workflow, possible reasons:
  1. You are not using the latest ComfyUI version (Nightly version)
  2. Some nodes failed to import at startup

Gemini 4 Hydrogen image to prompt

The official template loads one image, sends it to Gemini 4 Hydrogen together with a prompt that asks for a standard AI art positive prompt, then shows the reply in Preview Any and writes it to a text file. Gemini 4 Hydrogen workflow reading an image and writing a prompt

Download Workflow

Download JSON or search “Gemini 4 Hydrogen” in Template Library
Input materials

blue_poppies_field.png

LoadImage node · blue_poppies_field.png
  1. Load your image in the LoadImage node and connect it to the images input of the Google Gemini node.
  2. Edit the text in the Text (User Prompt) node if you want a different kind of answer. The template prompt asks for subject, composition, camera, lighting, color, texture and style, and for the positive prompt only.
  3. Run the workflow. The reply appears in Preview Any, and Save Text writes a .txt file under ComfyUI/output/Gemini/ whose name starts with Gemini4_Hydrogen. Inside the file, USER PROMPT: is followed by your prompt and OUTPUT: by the model’s reply.

Node settings that change the output

Hydrogen has no temperature or top_p widget. Output variation comes from the prompt, the thinking level and the seed, and deterministic output is not guaranteed.

Gemini 4 model family

The Google Gemini node exposes three Gemini 4 text models. They share one input set and differ in how hard they think and how long an answer they can return: Only Hydrogen ships with a template so far. To try Argon or Carbon, duplicate the Hydrogen workflow and switch the model dropdown; the rest of the graph stays the same.

Notes

The Gemini 4 Hydrogen template requires ComfyUI 0.46.0 or later. Earlier builds do not list the Gemini 4 models in the Google Gemini node. There is no Comfy Cloud version of this template yet.
  • This workflow runs on your Comfy account and is billed in the same credits as the other partner nodes. See Partner Nodes pricing for per-model rates and Concurrency limits for how many requests you can have in flight.
  • The original Gemini chat workflow, including the Batch Images example, stays on the Google Gemini page.