> ## Documentation Index > Fetch the complete documentation index at: https://docs.stability.ai/llms.txt > Use this file to discover all available pages before exploring further. # Stable Image Ultra > Our most advanced text to image generation service, Stable Image Ultra creates the highest quality images with unprecedented prompt understanding. Ultra excels in typography, complex compositions, dynamic lighting, vibrant hues, and overall cohesion and structure of an art piece. Made from the most advanced models, including Stable Diffusion 3.5, Ultra offers the best of the Stable Diffusion ecosystem. ### Try it out Grab your [API key](https://platform.stability.ai/account/keys) and head over to [![Open Google Colab](https://platform.stability.ai/svg/google-colab.svg)](https://colab.research.google.com/github/stability-ai/stability-sdk/blob/main/nbs/Stable_Image_API_Public.ipynb#scrollTo=yXhs626oZdr1) ### How to use Please invoke this endpoint with a `POST` request. The headers of the request must include an API key in the `authorization` field. The body of the request must be `multipart/form-data`. The accept header should be set to one of the following: - `image/*` to receive the image in the format specified by the `output_format` parameter. - `application/json` to receive the image in the format specified by the `output_format` parameter, but encoded to base64 in a JSON response. The only required parameter is the `prompt` field, which should contain the text prompt for the image generation. The body of the request should include: - `prompt` - text to generate the image from The body may optionally include: - `image` - the image to use as the starting point for the generation - `strength` - controls how much influence the `image` parameter has on the output image - `aspect_ratio` - the aspect ratio of the output image - `negative_prompt` - keywords of what you **do not** wish to see in the output image - `seed` - the randomness seed to use for the generation - `output_format` - the format of the output image > **Note:** for the full list of optional parameters, please see the request schema below. ### Output The resolution of the generated image will be 1 megapixel. The default resolution is 1024x1024. ### Credits The Ultra service uses 8 credits per successful result. You will not be charged for failed results. ## OpenAPI ````yaml /openapi.json post /v2beta/stable-image/generate/ultra openapi: 3.0.1 info: version: v2beta title: StabilityAI REST API description: >- Welcome to the Stability Platform API. As of March 2024, we are building the REST v2beta API service to be the primary API service for the Stability Platform. All AI services on other APIs (gRPC, REST v1, RESTv2alpha) will continue to be maintained, however they will not receive new features or parameters. If you are a REST v2alpha user, we strongly recommend that you adjust the URL calls for the specific services that you are using over to the equivalent REST v2beta URL. Normally, this means simply replacing "v2alpha" with "v2beta". We are not deprecating v2alpha URLs at this time for users that are currently using them. #### Authentication You will need your [Stability API key](https://platform.stability.ai/account/keys) in order to make requests to this API. Make sure you never share your API key with anyone, and you never commit it to a public repository. Include this key in the `Authorization` header of your requests. #### Rate limiting This API is rate-limited to 150 requests every 10 seconds. If you exceed this limit, you will receive a `429` response and be timed out for 60 seconds. If you find this limit too restrictive, please reach out to us via [this form](https://kb.stability.ai/knowledge-base/kb-tickets/new). #### Support Please see our [FAQ](https://platform.stability.ai/faq) for answers to common questions. If you have any other questions or concerns, please reach out to us via [this form](https://kb.stability.ai/knowledge-base/kb-tickets/new). To see the health of our APIs, please check our [Status Page](https://stabilityai.instatus.com/). servers: - url: https://api.stability.ai security: - STABILITY_API_KEY: [] tags: - name: Edit description: >- Tools for editing your own and generated images. **[Erase](/docs/api-reference#tag/Edit/paths/~1v2beta~1stable-image~1edit~1erase/post)** The Erase service removes unwanted objects, such as blemishes on portraits or items on desks, using image masks. **[Outpaint](/docs/api-reference#tag/Edit/paths/~1v2beta~1stable-image~1edit~1outpaint/post)** The outpaint service inserts additional content in an image to fill in the space in any direction, allowing you to "zoom-out" of an image. **[Inpaint](/docs/api-reference#tag/Edit/paths/~1v2beta~1stable-image~1edit~1inpaint/post)** The Inpaint service modifies images by filling in or replacing specified areas with new content based on the content of a "mask" image. **[Search and Replace](/docs/api-reference#tag/Edit/paths/~1v2beta~1stable-image~1edit~1search-and-replace/post)** The Search and Replace service, similar to inpaint, allows to replace specified areas with new content, but this time with the help of a prompt instead of a mask. The service will automatically segment the object and replace it with the object requested in the prompt. **[Search and Recolor](/docs/api-reference#tag/Edit/paths/~1v2beta~1stable-image~1edit~1search-and-recolor/post)** The Search and Recolor service is another derivative of the inpaint service and provides the ability to change the color of a specific object in an image using a prompt. The Search and Recolor service will automatically segment the object and recolor it using the colors requested in the prompt. **[Remove Background](/docs/api-reference#tag/Edit/paths/~1v2beta~1stable-image~1edit~1remove-background/post)** The Remove Background service accurately segments the foreground from an image to removes the background. - name: Upscale description: >- Tools for increasing the size and resolution of your existing images. **[Fast Upscaler](/docs/api-reference#tag/Upscale/paths/~1v2beta~1stable-image~1upscale~1fast/post)** This service enhances image resolution by 4x using predictive and generative AI. This lightweight and fast service (processing in ~1 second) is ideal for enhancing the quality of compressed images, making it suitable for social media posts and other applications. **[Conservative Upscaler](/docs/api-reference#tag/Upscale/paths/~1v2beta~1stable-image~1upscale~1conservative/post)** This service can upscale images by 20 to 40 times up to a 4 megapixel output image with minimal alteration to the original image. The Conservative Upscaler can upscale images as small as 64x64 pixels directly to a 4 megapixel output. Use this option if you directly need a 4 megapixel output. **[Creative Upscaler](/docs/api-reference#tag/Upscale/paths/~1v2beta~1stable-image~1upscale~1creative/post)** The service can upscale highly degraded images (lower than 1 megapixel) with a creative twist to provide high resolution results. - name: Generate description: >- Tools to generate new images from text, or create variations of existing images. Our different services include: **[Stable Image Ultra](/docs/api-reference#tag/Generate/paths/~1v2beta~1stable-image~1generate~1ultra/post)**: Photorealistic, Large-Scale Output Our state of the art text to image model based on Stable Diffusion 3.5. Stable Image Ultra Produces the highest quality, photorealistic outputs perfect for professional print media and large format applications. Stable Image Ultra excels at rendering exceptional detail and realism. **[Stable Image Core](/docs/api-reference#tag/Generate/paths/~1v2beta~1stable-image~1generate~1core/post)**: Fast and Affordable Optimized for fast and affordable image generation, great for rapidly iterating on concepts during ideation. Stable Image Core is the next generation model following Stable Diffusion XL. **[Stable Diffusion 3.5 Model Suite](/docs/api-reference#tag/Generate/paths/~1v2beta~1stable-image~1generate~1sd3/post)**: Stability AI's latest base models The different versions of our open models are available via API, letting you test and adjust speed and quality based on your use case. All model versions strike a balance between generation speed and output quality and are ideal for creating high-volume, high-quality digital assets like websites, newsletters, and marketing materials. - name: Control description: >- Tools for generating precise, controlled variations of existing images or sketches. **[Sketch](/docs/api-reference#tag/Control/paths/~1v2beta~1stable-image~1control~1sketch/post)** This service upgrades sketches to refined outputs with precise control. For non-sketch images, it allows detailed manipulation of the final appearance by leveraging the contour lines and edges within the image. **[Structure](/docs/api-reference#tag/Control/paths/~1v2beta~1stable-image~1control~1structure/post)** This service excels in generating images by maintaining the structure of an input image, making it especially valuable for advanced content creation scenarios such as recreating scenes or rendering characters from models. **[Style](/docs/api-reference#tag/Control/paths/~1v2beta~1stable-image~1control~1style/post)** This service extracts stylistic elements from an input image (control image) and uses it to guide the creation of an output image based on the prompt. The result is a new image in the same style as the control image. - name: Results description: Tools for fetching the results of your async generations. - name: Stable Audio 2 description: >- Tools to generate music and sound from text or audio, or transform existing audio clips into new compositions. Our different services include: **Stable Audio 2.5**: Fast, Best-Quality, Long-Form Music & Audio Generation Our most advanced audio generation model, capable of generating up to 3-minute, 44.1 kHz stereo compositions. Stable Audio 2.5 supports text-to-audio, audio-to-audio, and audio-inpaint workflows - allowing creators to upload a sound and transform it into new instruments, styles, or genres using natural language prompts. Ideal for music production, cinematic sound design, and remixing. **Stable Audio 2.0**: High-Quality Audio Generation Built for text-to-audio and audio-to-audio generation, also capable of generating up to 3-minute, 44.1 kHz stereo. Stable Audio 2.0 is great for ideation, music demos, and ambient soundscapes. It's optimized for creative professionals seeking detailed and extended outputs from simple prompts. Stable Audio models were exclusively trained on licensed data from the [AudioSparx](https://www.audiosparx.com/) music library, honoring opt-out requests and ensuring fair compensation for creators. Additionally, Stable Audio 2.5 was pre-trained on licensed data from [Freesound](https://freesound.org/). Read more about the model capabilities [here](https://stability.ai/news/stable-audio-2-0). x-displayName: Stable Audio 2.5 - name: Stable Audio description: >- Tools to generate music and sound from text or audio, or transform existing audio clips into new compositions. Our different services include: **Stable Audio 3.0**: Fast, Best-Quality, Long-Form Music & Audio Generation Our most advanced audio generation model, capable of generating up to 6-minute, 44.1 kHz stereo compositions. Stable Audio 3.0 supports text-to-audio, audio-to-audio, and audio-inpaint workflows - allowing creators to upload a sound and transform it into new instruments, styles, or genres using natural language prompts. Ideal for music production, cinematic sound design, and remixing. Stable Audio models were exclusively trained on licensed data from the [AudioSparx](https://www.audiosparx.com/) music library, honoring opt-out requests and ensuring fair compensation for creators. Additionally, Stable Audio 3.0 was pre-trained on licensed data from [Freesound](https://freesound.org/). Read more about the model capabilities [here](https://stability.ai/news/stable-audio-3-0). x-displayName: Stable Audio 3.0 paths: /v2beta/stable-image/generate/ultra: post: tags: - Generate summary: Stable Image Ultra description: >- Our most advanced text to image generation service, Stable Image Ultra creates the highest quality images with unprecedented prompt understanding. Ultra excels in typography, complex compositions, dynamic lighting, vibrant hues, and overall cohesion and structure of an art piece. Made from the most advanced models, including Stable Diffusion 3.5, Ultra offers the best of the Stable Diffusion ecosystem. ### Try it out Grab your [API key](https://platform.stability.ai/account/keys) and head over to [![Open Google Colab](https://platform.stability.ai/svg/google-colab.svg)](https://colab.research.google.com/github/stability-ai/stability-sdk/blob/main/nbs/Stable_Image_API_Public.ipynb#scrollTo=yXhs626oZdr1) ### How to use Please invoke this endpoint with a `POST` request. The headers of the request must include an API key in the `authorization` field. The body of the request must be `multipart/form-data`. The accept header should be set to one of the following: - `image/*` to receive the image in the format specified by the `output_format` parameter. - `application/json` to receive the image in the format specified by the `output_format` parameter, but encoded to base64 in a JSON response. The only required parameter is the `prompt` field, which should contain the text prompt for the image generation. The body of the request should include: - `prompt` - text to generate the image from The body may optionally include: - `image` - the image to use as the starting point for the generation - `strength` - controls how much influence the `image` parameter has on the output image - `aspect_ratio` - the aspect ratio of the output image - `negative_prompt` - keywords of what you **do not** wish to see in the output image - `seed` - the randomness seed to use for the generation - `output_format` - the format of the output image > **Note:** for the full list of optional parameters, please see the request schema below. ### Output The resolution of the generated image will be 1 megapixel. The default resolution is 1024x1024. ### Credits The Ultra service uses 8 credits per successful result. You will not be charged for failed results. parameters: - $ref: '#/components/parameters/Authorization' - $ref: '#/components/parameters/FormDataContentType' - $ref: '#/components/parameters/AcceptImage' - $ref: '#/components/parameters/StabilityClientID' - $ref: '#/components/parameters/StabilityClientUserID' - $ref: '#/components/parameters/StabilityClientVersion' requestBody: content: multipart/form-data: schema: type: object properties: prompt: $ref: '#/components/schemas/Prompt' negative_prompt: $ref: '#/components/schemas/NegativePrompt' aspect_ratio: $ref: '#/components/schemas/AspectRatio' seed: $ref: '#/components/schemas/Seed' output_format: type: string enum: - jpeg - png - webp default: png description: Dictates the `content-type` of the generated image. image: type: string description: >- The image to use as the starting point for the generation. > **Important:** The `strength` parameter is required when `image` is provided. Supported Formats: - jpeg - png - webp Validation Rules: - Width must be between 64 and 16,384 pixels - Height must be between 64 and 16,384 pixels - Total pixel count must be at least 4,096 pixels format: binary example: ./some/image.png style_preset: $ref: '#/components/schemas/StylePreset' strength: type: number minimum: 0 maximum: 1 description: >- Sometimes referred to as _denoising_, this parameter controls how much influence the `image` parameter has on the generated image. A value of 0 would yield an image that is identical to the input. A value of 1 would be as if you passed in no image at all. > **Important:** This parameter is required when `image` is provided. required: - prompt responses: '200': description: Generation was successful. headers: x-request-id: $ref: '#/components/headers/RequestID' content-type: description: |- The format of the generated image. To receive the bytes of the image directly, specify `image/*` in the accept header. To receive the bytes base64 encoded inside of a JSON payload, specify `application/json`. examples: jpeg: description: raw bytes value: image/jpeg jpegJSON: description: base64 encoded value: application/json; type=image/jpeg png: description: raw bytes value: image/png pngJSON: description: base64 encoded value: application/json; type=image/png webp: description: raw bytes value: image/webp webpJSON: description: base64 encoded value: application/json; type=image/webp schema: type: string finish-reason: $ref: '#/components/headers/ImageFinishReason' seed: $ref: '#/components/headers/Seed' content: image/jpeg: example: The bytes of the generated jpeg schema: $ref: '#/components/schemas/ImageBinaryResponse' application/json; type=image/jpeg: schema: $ref: '#/components/schemas/ImageJSONResponse' image/png: example: The bytes of the generated png schema: $ref: '#/components/schemas/ImageBinaryResponse' application/json; type=image/png: schema: $ref: '#/components/schemas/ImageJSONResponse' image/webp: example: The bytes of the generated webp schema: $ref: '#/components/schemas/ImageBinaryResponse' application/json; type=image/webp: schema: $ref: '#/components/schemas/ImageJSONResponse' '400': $ref: '#/components/responses/BadRequest' '403': $ref: '#/components/responses/ContentModerated' '413': $ref: '#/components/responses/PayloadTooLarge' '422': $ref: '#/components/responses/ImageClassificationFailed' '429': $ref: '#/components/responses/RateLimited' '500': $ref: '#/components/responses/InternalError' x-codeSamples: - lang: python label: Python source: |- import requests response = requests.post( f"https://api.stability.ai/v2beta/stable-image/generate/ultra", headers={ "authorization": f"Bearer sk-MYAPIKEY", "accept": "image/*" }, files={"none": ''}, data={ "prompt": "Lighthouse on a cliff overlooking the ocean", "output_format": "webp", }, ) if response.status_code == 200: with open("./lighthouse.webp", 'wb') as file: file.write(response.content) else: raise Exception(str(response.json())) - lang: javascript label: JavaScript source: |- import fs from "node:fs"; import axios from "axios"; import FormData from "form-data"; const payload = { prompt: "Lighthouse on a cliff overlooking the ocean", output_format: "webp" }; const response = await axios.postForm( `https://api.stability.ai/v2beta/stable-image/generate/ultra`, axios.toFormData(payload, new FormData()), { validateStatus: undefined, responseType: "arraybuffer", headers: { Authorization: `Bearer sk-MYAPIKEY`, Accept: "image/*" }, }, ); if(response.status === 200) { fs.writeFileSync("./lighthouse.webp", Buffer.from(response.data)); } else { throw new Error(`${response.status}: ${response.data.toString()}`); } - lang: terminal label: cURL source: >- curl -f -sS "https://api.stability.ai/v2beta/stable-image/generate/ultra" \ -H "authorization: Bearer sk-MYAPIKEY" \ -H "accept: image/*" \ -F prompt="Lighthouse on a cliff overlooking the ocean" \ -F output_format="webp" \ -o "./lighthouse.webp" components: parameters: Authorization: schema: type: string description: >- Your [Stability API key](https://platform.stability.ai/account/keys), used to authenticate your requests. Although you may have multiple keys in your account, you should use the same key for all requests to this API. minLength: 1 required: true name: authorization in: header FormDataContentType: schema: type: string minLength: 1 description: >- The content type of the request body. Do not manually specify this header; your HTTP client library will automatically include the appropriate boundary parameter. example: multipart/form-data required: true name: content-type in: header AcceptImage: schema: type: string default: image/* description: >- Specify `image/*` to receive the bytes of the image directly. Otherwise specify `application/json` to receive the image as base64 encoded JSON. enum: - image/* - application/json required: false name: accept in: header StabilityClientID: schema: type: string maxLength: 256 description: >- The name of your application, used to help us communicate app-specific debugging or moderation issues to you. example: my-awesome-app required: false name: stability-client-id in: header StabilityClientUserID: schema: type: string maxLength: 256 description: >- A unique identifier for your end user. Used to help us communicate user-specific debugging or moderation issues to you. Feel free to obfuscate this value to protect user privacy. example: DiscordUser#9999 required: false name: stability-client-user-id in: header StabilityClientVersion: schema: type: string maxLength: 256 description: >- The version of your application, used to help us communicate version-specific debugging or moderation issues to you. example: 1.2.1 required: false name: stability-client-version in: header schemas: Prompt: type: string minLength: 1 maxLength: 10000 description: >- What you wish to see in the output image. A strong, descriptive prompt that clearly defines elements, colors, and subjects will lead to better results. To control the weight of a given word use the format `(word:weight)`, where `word` is the word you'd like to control the weight of and `weight` is a value between 0 and 1. For example: `The sky was a crisp (blue:0.3) and (green:0.8)` would convey a sky that was blue and green, but more green than blue. NegativePrompt: type: string maxLength: 10000 description: >- A blurb of text describing what you **do not** wish to see in the output image. This is an advanced feature. AspectRatio: type: string enum: - '21:9' - '16:9' - '3:2' - '5:4' - '1:1' - '4:5' - '2:3' - '9:16' - '9:21' default: '1:1' description: Controls the aspect ratio of the generated image. Seed: type: number minimum: 0 maximum: 4294967294 default: 0 description: >- A specific value that is used to guide the 'randomness' of the generation. (Omit this parameter or pass `0` to use a random seed.) StylePreset: type: string enum: - enhance - anime - photographic - digital-art - comic-book - fantasy-art - line-art - analog-film - neon-punk - isometric - low-poly - origami - modeling-compound - cinematic - 3d-model - pixel-art - tile-texture description: Guides the image model towards a particular style. ImageBinaryResponse: type: string description: |- The bytes of the generated image. The `finish-reason` and `seed` will be present as headers. format: binary ImageJSONResponse: type: object properties: image: type: string description: The generated image, encoded to base64. example: AAAAIGZ0eXBpc29tAAACAGlzb21pc28yYXZjMW1... seed: allOf: - $ref: '#/components/schemas/Seed' - description: The seed used as random noise for this generation. example: 343940597 finish_reason: type: string enum: - SUCCESS - CONTENT_FILTERED description: >- The reason the generation finished. - `SUCCESS` = successful generation. - `CONTENT_FILTERED` = successful generation, however the output violated our content moderation policy and has been blurred as a result. example: SUCCESS required: - image - finish_reason Error: type: object properties: id: type: string minLength: 1 description: >- A unique identifier associated with this error. Please include this in any [support tickets](https://kb.stability.ai/knowledge-base/kb-tickets/new) you file, as it will greatly assist us in diagnosing the root cause of the problem. example: a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4 name: type: string minLength: 1 description: >- Short-hand name for an error, useful for discriminating between errors with the same status code. example: bad_request errors: type: array items: type: string minItems: 1 description: One or more error messages indicating what went wrong. example: - 'some-field: is required' required: - id - name - errors ContentModerationResponse: type: object properties: id: type: string minLength: 1 description: >- A unique identifier associated with this error. Please include this in any [support tickets](https://kb.stability.ai/knowledge-base/kb-tickets/new) you file, as it will greatly assist us in diagnosing the root cause of the problem. example: a1b2c3d4e5f6a1b2c3d4e5f6a1b2c3d4 name: type: string minLength: 1 description: >- Our content moderation system has flagged some part of your request and subsequently denied it. You were not charged for this request. While this may at times be frustrating, it is necessary to maintain the integrity of our platform and ensure a safe experience for all users. If you would like to provide feedback, please use the [Support Form](https://kb.stability.ai/knowledge-base/kb-tickets/new). enum: - content_moderation errors: type: array items: type: string minItems: 1 description: One or more error messages indicating what went wrong. example: - 'some-field: is required' required: - id - name - errors description: Your request was flagged by our content moderation system. example: id: ed14db44362126aab3cbd25cca51ffe3 name: content_moderation errors: - >- Your request was flagged by our content moderation system, as a result your request was denied and you were not charged. headers: RequestID: description: A unique identifier for this request. schema: type: string ImageFinishReason: schema: type: string enum: - SUCCESS - CONTENT_FILTERED description: >- Indicates the reason the generation finished. - `SUCCESS` = successful generation. - `CONTENT_FILTERED` = successful generation, however the output violated our content moderation policy and has been blurred as a result. > **NOTE:** This header is absent on JSON encoded responses because it is present in the body as `finish_reason`. Seed: description: >- The seed used as random noise for this generation. > **NOTE:** This header is absent on JSON encoded responses because it is present in the body as `seed`. example: '343940597' schema: type: string responses: BadRequest: description: Invalid parameter(s), see the `errors` field for details. content: application/json: schema: $ref: '#/components/schemas/Error' ContentModerated: description: Your request was flagged by our content moderation system. content: application/json: schema: $ref: '#/components/schemas/ContentModerationResponse' PayloadTooLarge: description: Your request was larger than 10MiB. content: application/json: schema: $ref: '#/components/schemas/Error' example: id: 4212a4b66fbe1cedca4bf2133d35dca5 name: payload_too_large errors: - 'body: payloads cannot be larger than 10MiB in size' ImageClassificationFailed: description: >- Your request was well-formed, but rejected. See the `errors` field for details. content: application/json: schema: $ref: '#/components/schemas/Error' examples: Invalid Language: value: id: ff54b236a3acdde1522cb1ba641c43ed name: invalid_language errors: - English is the only supported language for this service. Public Figure Detected: value: id: ff54b236a3acdde1522cb1ba641c43ed name: public_figure errors: - >- Our system detected the likeness of a public figure in your image. To comply with our guidelines, this request cannot be processed. Please upload a different image. RateLimited: description: You have made more than 150 requests in 10 seconds. content: application/json: schema: $ref: '#/components/schemas/Error' example: id: rate_limit_exceeded name: rate_limit_exceeded errors: - >- You have exceeded the rate limit of 150 requests within a 10 second period, and have been timed out for 60 seconds. InternalError: description: >- An internal error occurred. If the problem persists [contact support](https://kb.stability.ai/knowledge-base/kb-tickets/new). content: application/json: schema: $ref: '#/components/schemas/Error' example: id: 2a1b2d4eafe2bc6ab4cd4d5c6133f513 name: internal_error errors: - An unexpected server error has occurred, please try again later. securitySchemes: STABILITY_API_KEY: type: apiKey name: authorization in: header description: >- Use your [Stability API key](https://platform.stability.ai/account/keys) to authentication requests to this App. ````