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Model infoModelsSnapshot: 15 Oct 2026

Stability AI / Stable Image managed services

Stable Image Ultra

Image generation from a prompt, optionally guided by a source image. This managed service uses a changing combination of Stability models.

Image generation
availableClosed weightsImage generation
Official documentation (opens in a new tab)Reviewed 13 Oct 2026
10 of 24 specification fields collected
Output resolution1 megapixel; default 1024×1024See specification notes below
Text input limit10,000 charactersSee specification notes below
Input billingSee ratesStability AI API
Output billingSee ratesPublished units and conditions below

Specifications

Provider-documented facts. “Not collected” means we have not verified that field yet, not that the feature is unsupported.

Context / input limit
Not collected
Maximum output
Not collected
Input modalities
Text, ImageSource for Input modalities (opens in a new tab)
Output modalities
ImageSource for Output modalities (opens in a new tab)
Reasoning
Not collected
Tool calling
Not collected
Structured output
Not collected
Streaming
Not collected
Batch processing
Not collected
Fine-tuning
Not collected
Knowledge cutoff
Not collected
Release date
Not collected
Parameters
Not collected
Architecture
Not collected
Languages
Not collected
Context caching
Not collected
Maximum prompt characters
10,000 charactersSource for Maximum prompt characters (opens in a new tab)
Output formats
JPEG, PNG, WEBPSource for Output formats (opens in a new tab)
Aspect ratios
21:9, 16:9, 3:2, 5:4, 1:1, 4:5, 2:3, 9:16, 9:21Source for Aspect ratios (opens in a new tab)
Seed control
0–4,294,967,294; zero or an omitted seed selects randomnessSource for Seed control (opens in a new tab)
Negative prompts
SupportedSource for Negative prompts (opens in a new tab)
Input file formats
JPEG, PNG, WEBPSource for Input file formats (opens in a new tab)
Image input limits
Width and height: 64–16,384 px; At least 4,096 total pixelsSource for Image input limits (opens in a new tab)

Bounds apply to the principal source image; masks and auxiliary references have their own fields.

Output resolutions
1 megapixel; default 1024×1024Source for Output resolutions (opens in a new tab)

Access & pricing

Prices belong to an endpoint and billing tier. A provider listing does not guarantee access for every account or region.

Stability AI API

Provider source (opens in a new tab)
API model ID
Not collected

No pinned model selector established for this access path.

Access
Developer account, API key and credits required. Public documentation and contracts reviewed; no inference request was made.
Regions
Not established for this endpoint; account availability is not a data-residency guarantee.
API endpoint URL
POST https://api.stability.ai/v2beta/stable-image/generate/ultraSource for API endpoint URL (opens in a new tab)
Request mode
Returns the completed media in the responseSource for Request mode (opens in a new tab)

JSON or base64 transport does not establish structured model output, streaming or a batch API.

Required request fields
promptSource for Required request fields (opens in a new tab)
Maximum prompt characters
10,000 charactersSource for Maximum prompt characters (opens in a new tab)
Output formats
JPEG, PNG, WEBPSource for Output formats (opens in a new tab)
Aspect ratios
21:9, 16:9, 3:2, 5:4, 1:1, 4:5, 2:3, 9:16, 9:21Source for Aspect ratios (opens in a new tab)
Seed control
0–4,294,967,294; zero or an omitted seed selects randomnessSource for Seed control (opens in a new tab)
Negative prompts
SupportedSource for Negative prompts (opens in a new tab)
Input modalities
Text, ImageSource for Input modalities (opens in a new tab)
Output modalities
ImageSource for Output modalities (opens in a new tab)
Input file formats
JPEG, PNG, WEBPSource for Input file formats (opens in a new tab)
Image input limits
Width and height: 64–16,384 px; At least 4,096 total pixelsSource for Image input limits (opens in a new tab)

Bounds apply to the principal source image; masks and auxiliary references have their own fields.

Generation controls
strength: 0–1Source for Generation controls (opens in a new tab)
Reference images
Optional source image; strength is required when suppliedSource for Reference images (opens in a new tab)

Prices retain their published currencies and billing units below.

Published billing units · original currency · observed 13 Oct 2026
CategoryUsageRateUnit
ImageStable Image Ultra1$0.08successful generation

Rate conditions

  1. 8 credits × published $0.01/credit. Direct API flat rate; failed generations are not charged. No text-token or per-question conversion.
Pricing source (opens in a new tab)

Data & enterprise terms

Stability terms permit using content to improve services and describe a training opt-out. This is not a default no-training or zero-retention guarantee. Partner contracts may differ; enterprise terms must be verified separately.

Read the service policy (opens in a new tab)

Amazon Bedrock

Provider source (opens in a new tab)
API model ID
stability.stable-image-ultra-v1:1
Access
AWS account and permitted Bedrock model access required. Host model card reviewed; separate Bedrock rates not yet captured.
Regions
us-west-2 (Oregon), as listed in the reviewed Bedrock model card
Input modalities
TextSource for Input modalities (opens in a new tab)
Output modalities
ImageSource for Output modalities (opens in a new tab)
Endpoint caveat
Bedrock calls this release 1.0 and exposes the v1:1 selector. The direct API is an unpinned service; cross-host checkpoint equivalence is not established.Source for Endpoint caveat (opens in a new tab)

Endpoint pricing has not been collected. Check the provider for applicable rates.

Data & enterprise terms

Stability terms permit using content to improve services and describe a training opt-out. This is not a default no-training or zero-retention guarantee. Partner contracts may differ; enterprise terms must be verified separately.

Read the service policy (opens in a new tab)

Caching

Caching can reuse earlier input processing. Availability, lifetime and billing depend on the endpoint. A cache hit still generates a new response.

01 / INITIAL INPUTProcess & retain

The system processes eligible input and retains reusable state.

02 / LATER REQUESTCheck available state

Reuse depends on matching input, session state and the cache policy.

03 / CACHE HITReuse & generate

Reusing state can reduce repeated work. Any charges follow the billing rules below.

Stability AI API

Not verified
How it works
Not collected
Minimum reusable input
Not collected
Lifetime & refresh
Not collected
How to enable it
Not collected
Usage fields
Not collected
Billing rules
Not collected
Limits & data boundaries
Not collected

No verified cache rate for this endpoint. An empty rate is not a zero charge.

Amazon Bedrock

stability.stable-image-ultra-v1:1
Not verified
How it works
Not collected
Minimum reusable input
Not collected
Lifetime & refresh
Not collected
How to enable it
Not collected
Usage fields
Not collected
Billing rules
Not collected
Limits & data boundaries
Not collected

No verified cache rate for this endpoint. An empty rate is not a zero charge.

What the measurements say

No benchmark observations have been added for this model. We do not turn a vendor description into a performance score.

Latency and throughput depend on the host, request size, reasoning settings and load. There is no measured speed or global usage figure in this record.

The record behind the model

Why it is included

This record identifies a proprietary hosted release or an explicitly labeled managed service under Stability’s service terms, which prohibit reverse engineering. It does not reclassify publicly downloadable Stable Diffusion base weights as closed. Service-specific fine-tunes and orchestration are not distributed as the corresponding base-model weight release; exact internal checkpoint lineage remains unverified.

Classification evidence (opens in a new tab)

Sources reviewed