> ## Documentation Index > Fetch the complete documentation index at: https://docs.comfy.org/llms.txt > Use this file to discover all available pages before exploring further. # Flux 1.1 [pro] Ultra Image - ComfyUI Native Node Documentation > Create images using Black Forest Labs' high-resolution image generation API ComfyUI Native Flux 1.1 [pro] Ultra Image node The Flux 1.1 \[pro] Ultra Image node allows you to generate ultra-high-resolution images through text prompts, directly connecting to Black Forest Labs' latest image generation API. This node supports two main usage modes: 1. **Text-to-Image**: Generate high-quality images from text prompts (when no image input is used) 2. **Image-to-Image**: Combine existing images with prompts to create new images that blend features from both (Remix mode) This node supports Ultra mode through API calls, capable of generating images at 4 times the resolution of standard Flux 1.1 \[pro] (up to 4MP), without sacrificing prompt adherence, and maintaining super-fast generation times of just 10 seconds. Compared to other high-resolution models, it's more than 2.5 times faster. ## Parameter Description ### Basic Parameters | Parameter | Type | Default | Description | | ------------------ | ------- | ------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | prompt | String | "" | Text description for generating the image | | prompt\_upsampling | Boolean | False | Whether to use prompt upsampling technique to enhance details. When enabled, automatically modifies prompts for more creative generation, but results become non-deterministic (same seed won't produce exactly the same result) | | seed | Integer | 0 | Random seed value, controls generation randomness | | aspect\_ratio | String | "16:9" | Width-to-height ratio of the image, must be between 1:4 and 4:1 | | raw | Boolean | False | When set to True, generates less processed, more natural-looking images | ### Optional Parameters | Parameter | Type | Default | Description | | ----------------------- | ----- | ------- | --------------------------------------------------------------------------------------------------------------------------------------------------------- | | image\_prompt | Image | None | Optional input, used for Image-to-Image (Remix) mode | | image\_prompt\_strength | Float | 0.1 | Active when `image_prompt` is input, adjusts the blend between prompt and image prompt. Higher values make output closer to input image, range is 0.0-1.0 | ### Output | Output | Type | Description | | ------ | ----- | -------------------------------------- | | IMAGE | Image | Generated high-resolution image result | ## Usage Examples Please visit the tutorial below to see corresponding usage examples * [Flux 1.1 Pro Ultra Image API Node ComfyUI Official Example Workflow](/tutorials/partner-nodes/black-forest-labs/flux-1-1-pro-ultra-image) ## How It Works Flux 1.1 \[pro] Ultra mode uses optimized deep learning architecture and efficient GPU acceleration technology to achieve high-resolution image generation without sacrificing speed. When a request is sent to the API, the system parses the prompt, applies appropriate parameters, then computes the image in parallel, finally generating and returning the high-resolution result. Compared to regular models, Ultra mode particularly focuses on detail preservation and consistency at large scales, ensuring impressive quality even at 4MP high resolution. ## Source Code \[Node Source Code (Updated on 2025-05-03)] ```python theme={null} class FluxProUltraImageNode(ComfyNodeABC): """ Generates images synchronously based on prompt and resolution. """ MINIMUM_RATIO = 1 / 4 MAXIMUM_RATIO = 4 / 1 MINIMUM_RATIO_STR = "1:4" MAXIMUM_RATIO_STR = "4:1" @classmethod def INPUT_TYPES(s): return { "required": { "prompt": ( IO.STRING, { "multiline": True, "default": "", "tooltip": "Prompt for the image generation", }, ), "prompt_upsampling": ( IO.BOOLEAN, { "default": False, "tooltip": "Whether to perform upsampling on the prompt. If active, automatically modifies the prompt for more creative generation, but results are nondeterministic (same seed will not produce exactly the same result).", }, ), "seed": ( IO.INT, { "default": 0, "min": 0, "max": 0xFFFFFFFFFFFFFFFF, "control_after_generate": True, "tooltip": "The random seed used for creating the noise.", }, ), "aspect_ratio": ( IO.STRING, { "default": "16:9", "tooltip": "Aspect ratio of image; must be between 1:4 and 4:1.", }, ), "raw": ( IO.BOOLEAN, { "default": False, "tooltip": "When True, generate less processed, more natural-looking images.", }, ), }, "optional": { "image_prompt": (IO.IMAGE,), "image_prompt_strength": ( IO.FLOAT, { "default": 0.1, "min": 0.0, "max": 1.0, "step": 0.01, "tooltip": "Blend between the prompt and the image prompt.", }, ), }, "hidden": { "auth_token": "AUTH_TOKEN_COMFY_ORG", }, } @classmethod def VALIDATE_INPUTS(cls, aspect_ratio: str): try: validate_aspect_ratio( aspect_ratio, minimum_ratio=cls.MINIMUM_RATIO, maximum_ratio=cls.MAXIMUM_RATIO, minimum_ratio_str=cls.MINIMUM_RATIO_STR, maximum_ratio_str=cls.MAXIMUM_RATIO_STR, ) except Exception as e: return str(e) return True RETURN_TYPES = (IO.IMAGE,) DESCRIPTION = cleandoc(__doc__ or "") # Handle potential None value FUNCTION = "api_call" API_NODE = True CATEGORY = "api node/image/bfl" def api_call( self, prompt: str, aspect_ratio: str, prompt_upsampling=False, raw=False, seed=0, image_prompt=None, image_prompt_strength=0.1, auth_token=None, **kwargs, ): operation = SynchronousOperation( endpoint=ApiEndpoint( path="/proxy/bfl/flux-pro-1.1-ultra/generate", method=HttpMethod.POST, request_model=BFLFluxProUltraGenerateRequest, response_model=BFLFluxProGenerateResponse, ), request=BFLFluxProUltraGenerateRequest( prompt=prompt, prompt_upsampling=prompt_upsampling, seed=seed, aspect_ratio=validate_aspect_ratio( aspect_ratio, minimum_ratio=self.MINIMUM_RATIO, maximum_ratio=self.MAXIMUM_RATIO, minimum_ratio_str=self.MINIMUM_RATIO_STR, maximum_ratio_str=self.MAXIMUM_RATIO_STR, ), raw=raw, image_prompt=( image_prompt if image_prompt is None else convert_image_to_base64(image_prompt) ), image_prompt_strength=( None if image_prompt is None else round(image_prompt_strength, 2) ), ), auth_token=auth_token, ) output_image = handle_bfl_synchronous_operation(operation) return (output_image,) ```