# OpenAI models

Canonical HTML page: [OpenAI models](<https://impossibl.com/openai>)
Markdown alternative: [OpenAI models as Markdown](<https://impossibl.com/openai.md>)

Access 41 models from OpenAI through the Impossibl API, including GPT Chat Latest, GPT-3.5 Turbo, and GPT-4 Turbo. Compare API pricing, context windows, and capabilities.

Select two or three models to [compare specifications and API costs](<https://impossibl.com/compare.md>). Model types and billing units are not interchangeable.

## Models

### [GPT Chat Latest](<https://impossibl.com/openai/chat-latest>)

GPT Chat Latest is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $5.00 per million input tokens. The advertised output rate is $30.00 per million output tokens.

- API identifier: `openai/chat-latest`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $5.00 per million input tokens; $30.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/chat-latest.md>)

### [GPT-3.5 Turbo](<https://impossibl.com/openai/gpt-3.5-turbo>)

GPT-3.5 Turbo is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 16,000 tokens. The advertised input rate is $0.50 per million input tokens. The advertised output rate is $1.50 per million output tokens.

- API identifier: `openai/gpt-3.5-turbo`
- Creator: OpenAI; model type: Text generation.
- Context window: 16,000 tokens; tool calling: Not published.
- Inputs: text; outputs: text.
- Base API pricing (USD): $0.50 per million input tokens; $1.50 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-3.5-turbo.md>)

### [GPT-4 Turbo](<https://impossibl.com/openai/gpt-4-turbo>)

GPT-4 Turbo is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 128,000 tokens. The advertised input rate is $10.00 per million input tokens. The advertised output rate is $30.00 per million output tokens.

- API identifier: `openai/gpt-4-turbo`
- Creator: OpenAI; model type: Text generation.
- Context window: 128,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $10.00 per million input tokens; $30.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-4-turbo.md>)

### [GPT-4.1](<https://impossibl.com/openai/gpt-4.1>)

GPT-4.1 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,000,000 tokens. The advertised input rate is $2.00 per million input tokens. The advertised output rate is $8.00 per million output tokens.

- API identifier: `openai/gpt-4.1`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,000,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $2.00 per million input tokens; $8.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-4.1.md>)

### [GPT-4.1 mini](<https://impossibl.com/openai/gpt-4.1-mini>)

GPT-4.1 mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,000,000 tokens. The advertised input rate is $0.40 per million input tokens. The advertised output rate is $1.60 per million output tokens.

- API identifier: `openai/gpt-4.1-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,000,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.40 per million input tokens; $1.60 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-4.1-mini.md>)

### [GPT-4.1 nano](<https://impossibl.com/openai/gpt-4.1-nano>)

GPT-4.1 nano is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,000,000 tokens. The advertised input rate is $0.10 per million input tokens. The advertised output rate is $0.40 per million output tokens.

- API identifier: `openai/gpt-4.1-nano`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,000,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.10 per million input tokens; $0.40 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-4.1-nano.md>)

### [GPT-4o](<https://impossibl.com/openai/gpt-4o>)

GPT-4o is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 128,000 tokens. The advertised input rate is $2.50 per million input tokens. The advertised output rate is $10.00 per million output tokens.

- API identifier: `openai/gpt-4o`
- Creator: OpenAI; model type: Text generation.
- Context window: 128,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $2.50 per million input tokens; $10.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-4o.md>)

### [GPT-4o mini](<https://impossibl.com/openai/gpt-4o-mini>)

GPT-4o mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 128,000 tokens. The advertised input rate is $0.15 per million input tokens. The advertised output rate is $0.60 per million output tokens.

- API identifier: `openai/gpt-4o-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 128,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.15 per million input tokens; $0.60 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-4o-mini.md>)

### [GPT-5](<https://impossibl.com/openai/gpt-5>)

GPT-5 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.25 per million input tokens. The advertised output rate is $10.00 per million output tokens.

- API identifier: `openai/gpt-5`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.25 per million input tokens; $10.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.md>)

### [GPT-5 Codex](<https://impossibl.com/openai/gpt-5-codex>)

GPT-5 Codex is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.25 per million input tokens. The advertised output rate is $10.00 per million output tokens.

- API identifier: `openai/gpt-5-codex`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.25 per million input tokens; $10.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5-codex.md>)

### [GPT-5 mini](<https://impossibl.com/openai/gpt-5-mini>)

GPT-5 mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $0.25 per million input tokens. The advertised output rate is $2.00 per million output tokens.

- API identifier: `openai/gpt-5-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.25 per million input tokens; $2.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5-mini.md>)

### [GPT-5 nano](<https://impossibl.com/openai/gpt-5-nano>)

GPT-5 nano is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $0.05 per million input tokens. The advertised output rate is $0.40 per million output tokens.

- API identifier: `openai/gpt-5-nano`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.05 per million input tokens; $0.40 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5-nano.md>)

### [GPT-5 Pro](<https://impossibl.com/openai/gpt-5-pro>)

GPT-5 Pro is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $15.00 per million input tokens. The advertised output rate is $120.00 per million output tokens.

- API identifier: `openai/gpt-5-pro`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $15.00 per million input tokens; $120.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5-pro.md>)

### [GPT-5.1](<https://impossibl.com/openai/gpt-5.1>)

GPT-5.1 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.25 per million input tokens. The advertised output rate is $10.00 per million output tokens.

- API identifier: `openai/gpt-5.1`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.25 per million input tokens; $10.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.1.md>)

### [GPT-5.1 Codex](<https://impossibl.com/openai/gpt-5.1-codex>)

GPT-5.1 Codex is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.25 per million input tokens. The advertised output rate is $10.00 per million output tokens.

- API identifier: `openai/gpt-5.1-codex`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.25 per million input tokens; $10.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.1-codex.md>)

### [GPT-5.1 Codex mini](<https://impossibl.com/openai/gpt-5.1-codex-mini>)

GPT-5.1 Codex mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $0.25 per million input tokens. The advertised output rate is $2.00 per million output tokens.

- API identifier: `openai/gpt-5.1-codex-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.25 per million input tokens; $2.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.1-codex-mini.md>)

### [GPT-5.2](<https://impossibl.com/openai/gpt-5.2>)

GPT-5.2 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.75 per million input tokens. The advertised output rate is $14.00 per million output tokens.

- API identifier: `openai/gpt-5.2`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.75 per million input tokens; $14.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.2.md>)

### [GPT-5.2 Codex](<https://impossibl.com/openai/gpt-5.2-codex>)

GPT-5.2 Codex is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.75 per million input tokens. The advertised output rate is $14.00 per million output tokens.

- API identifier: `openai/gpt-5.2-codex`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.75 per million input tokens; $14.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.2-codex.md>)

### [GPT-5.3 Codex](<https://impossibl.com/openai/gpt-5.3-codex>)

GPT-5.3 Codex is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $1.75 per million input tokens. The advertised output rate is $14.00 per million output tokens.

- API identifier: `openai/gpt-5.3-codex`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.75 per million input tokens; $14.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.3-codex.md>)

### [GPT-5.4](<https://impossibl.com/openai/gpt-5.4>)

GPT-5.4 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $2.50 per million input tokens. The advertised output rate is $15.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.4`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $2.50 per million input tokens; $15.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.4.md>)

### [GPT-5.4 mini](<https://impossibl.com/openai/gpt-5.4-mini>)

GPT-5.4 mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $0.75 per million input tokens. The advertised output rate is $4.50 per million output tokens.

- API identifier: `openai/gpt-5.4-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.75 per million input tokens; $4.50 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.4-mini.md>)

### [GPT-5.4 nano](<https://impossibl.com/openai/gpt-5.4-nano>)

GPT-5.4 nano is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 400,000 tokens. The advertised input rate is $0.20 per million input tokens. The advertised output rate is $1.25 per million output tokens.

- API identifier: `openai/gpt-5.4-nano`
- Creator: OpenAI; model type: Text generation.
- Context window: 400,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.20 per million input tokens; $1.25 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.4-nano.md>)

### [GPT-5.4 Pro](<https://impossibl.com/openai/gpt-5.4-pro>)

GPT-5.4 Pro is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $30.00 per million input tokens. The advertised output rate is $180.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.4-pro`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $30.00 per million input tokens; $180.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.4-pro.md>)

### [GPT-5.5](<https://impossibl.com/openai/gpt-5.5>)

GPT-5.5 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $5.00 per million input tokens. The advertised output rate is $30.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.5`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $5.00 per million input tokens; $30.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.5.md>)

### [GPT-5.5 Pro](<https://impossibl.com/openai/gpt-5.5-pro>)

GPT-5.5 Pro is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $30.00 per million input tokens. The advertised output rate is $180.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.5-pro`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $30.00 per million input tokens; $180.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.5-pro.md>)

### [GPT-5.6 Luna](<https://impossibl.com/openai/gpt-5.6-luna>)

GPT-5.6 Luna is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $0.20 per million input tokens. The advertised output rate is $1.20 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.6-luna`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $0.20 per million input tokens; $1.20 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.6-luna.md>)

### [GPT-5.6 Sol](<https://impossibl.com/openai/gpt-5.6-sol>)

GPT-5.6 Sol is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $4.00 per million input tokens. The advertised output rate is $20.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.6-sol`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $4.00 per million input tokens; $20.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.6-sol.md>)

### [GPT-5.6 Terra](<https://impossibl.com/openai/gpt-5.6-terra>)

GPT-5.6 Terra is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 1,050,000 tokens. The advertised input rate is $2.00 per million input tokens. The advertised output rate is $12.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-5.6-terra`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $2.00 per million input tokens; $12.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-5.6-terra.md>)

### [GPT-6 Astra](<https://impossibl.com/openai/gpt-6-astra>)

GPT-6 Astra is an OpenAI reasoning model for demanding coding, research, computer use, and document creation. It is designed to work through complex tasks from an initial request to a completed result. Its published context window is 1,050,000 tokens. The advertised input rate is $10.00 per million input tokens. The advertised output rate is $50.00 per million output tokens. Additional pricing brackets apply when the input exceeds a published context threshold.

- API identifier: `openai/gpt-6-astra`
- Creator: OpenAI; model type: Text generation.
- Context window: 1,050,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $10.00 per million input tokens; $50.00 per million output tokens. Above 272,000 input tokens per request, context-tier rates apply to the whole request.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-6-astra.md>)

### [GPT Image 2](<https://impossibl.com/openai/gpt-image-2>)

GPT Image 2 is a image generation model from OpenAI, available through the Impossibl API. Its published context window is 32,000 tokens. The advertised input rate is $5.00 per million input tokens. The advertised output rate is $30.00 per million output tokens.

- API identifier: `openai/gpt-image-2`
- Creator: OpenAI; model type: Image generation.
- Context window: 32,000 tokens; tool calling: Not published.
- Inputs: text; outputs: images.
- Base API pricing (USD): $5.00 per million input tokens; $30.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-image-2.md>)

### [GPT Image 2.5 Flare](<https://impossibl.com/openai/gpt-image-2.5-flare>)

GPT Image 2.5 Flare is a image generation model from OpenAI, available through the Impossibl API. Its published context window is 32,000 tokens. The advertised input rate is $5.00 per million input tokens. The advertised output rate is $30.00 per million output tokens.

- API identifier: `openai/gpt-image-2.5-flare`
- Creator: OpenAI; model type: Image generation.
- Context window: 32,000 tokens; tool calling: Not published.
- Inputs: text; outputs: images.
- Base API pricing (USD): $5.00 per million input tokens; $30.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-image-2.5-flare.md>)

### [GPT Image 2.5 Sunburst](<https://impossibl.com/openai/gpt-image-2.5-sunburst>)

GPT Image 2.5 Sunburst is a image generation model from OpenAI, available through the Impossibl API. Its published context window is 32,000 tokens. The advertised input rate is $5.00 per million input tokens. The advertised output rate is $30.00 per million output tokens.

- API identifier: `openai/gpt-image-2.5-sunburst`
- Creator: OpenAI; model type: Image generation.
- Context window: 32,000 tokens; tool calling: Not published.
- Inputs: text; outputs: images.
- Base API pricing (USD): $5.00 per million input tokens; $30.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-image-2.5-sunburst.md>)

### [GPT OSS 120B](<https://impossibl.com/openai/gpt-oss-120b>)

GPT OSS 120B is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 128,000 tokens. The advertised input rate is $0.35 per million input tokens. The advertised output rate is $0.75 per million output tokens.

- API identifier: `openai/gpt-oss-120b`
- Creator: OpenAI; model type: Text generation.
- Context window: 128,000 tokens; tool calling: Not published.
- Inputs: text; outputs: text.
- Base API pricing (USD): $0.35 per million input tokens; $0.75 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-oss-120b.md>)

### [GPT OSS 20B](<https://impossibl.com/openai/gpt-oss-20b>)

GPT OSS 20B is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 128,000 tokens. The advertised input rate is $0.075 per million input tokens. The advertised output rate is $0.30 per million output tokens.

- API identifier: `openai/gpt-oss-20b`
- Creator: OpenAI; model type: Text generation.
- Context window: 128,000 tokens; tool calling: Not published.
- Inputs: text; outputs: text.
- Base API pricing (USD): $0.075 per million input tokens; $0.30 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-oss-20b.md>)

### [GPT Transcribe](<https://impossibl.com/openai/gpt-transcribe>)

GPT Transcribe is a speech-to-text model from OpenAI, available through the Impossibl API. The advertised input rate is $0.0045 per minute of audio.

- API identifier: `openai/gpt-transcribe`
- Creator: OpenAI; model type: Speech to text.
- Context window: Not published; tool calling: Not published.
- Inputs: audio, text; outputs: text.
- Base API pricing (USD): $0.0045 per minute of audio.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/gpt-transcribe.md>)

### [OpenAI o1](<https://impossibl.com/openai/o1>)

OpenAI o1 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 200,000 tokens. The advertised input rate is $15.00 per million input tokens. The advertised output rate is $60.00 per million output tokens.

- API identifier: `openai/o1`
- Creator: OpenAI; model type: Text generation.
- Context window: 200,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $15.00 per million input tokens; $60.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/o1.md>)

### [OpenAI o3](<https://impossibl.com/openai/o3>)

OpenAI o3 is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 200,000 tokens. The advertised input rate is $2.00 per million input tokens. The advertised output rate is $8.00 per million output tokens.

- API identifier: `openai/o3`
- Creator: OpenAI; model type: Text generation.
- Context window: 200,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $2.00 per million input tokens; $8.00 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/o3.md>)

### [OpenAI o3-mini](<https://impossibl.com/openai/o3-mini>)

OpenAI o3-mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 200,000 tokens. The advertised input rate is $1.10 per million input tokens. The advertised output rate is $4.40 per million output tokens.

- API identifier: `openai/o3-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 200,000 tokens; tool calling: Not published.
- Inputs: text; outputs: text.
- Base API pricing (USD): $1.10 per million input tokens; $4.40 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/o3-mini.md>)

### [OpenAI o4-mini](<https://impossibl.com/openai/o4-mini>)

OpenAI o4-mini is a text generation model from OpenAI, available through the Impossibl API. Its published context window is 200,000 tokens. The advertised input rate is $1.10 per million input tokens. The advertised output rate is $4.40 per million output tokens.

- API identifier: `openai/o4-mini`
- Creator: OpenAI; model type: Text generation.
- Context window: 200,000 tokens; tool calling: Not published.
- Inputs: text, image; outputs: text.
- Base API pricing (USD): $1.10 per million input tokens; $4.40 per million output tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/o4-mini.md>)

### [Text Embedding 3 Large](<https://impossibl.com/openai/text-embedding-3-large>)

Text Embedding 3 Large is a embedding model from OpenAI, available through the Impossibl API. Its published context window is 8,192 tokens. The advertised input rate is $0.13 per million input tokens.

- API identifier: `openai/text-embedding-3-large`
- Creator: OpenAI; model type: Embeddings.
- Context window: 8,192 tokens; tool calling: Not published.
- Inputs: text; outputs: embedding vectors.
- Base API pricing (USD): $0.13 per million input tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/text-embedding-3-large.md>)

### [Text Embedding 3 Small](<https://impossibl.com/openai/text-embedding-3-small>)

Text Embedding 3 Small is a embedding model from OpenAI, available through the Impossibl API. Its published context window is 8,192 tokens. The advertised input rate is $0.02 per million input tokens.

- API identifier: `openai/text-embedding-3-small`
- Creator: OpenAI; model type: Embeddings.
- Context window: 8,192 tokens; tool calling: Not published.
- Inputs: text; outputs: embedding vectors.
- Base API pricing (USD): $0.02 per million input tokens.
- [Complete model facts, cache rates, context tiers, and FAQs as Markdown](<https://impossibl.com/openai/text-embedding-3-small.md>)

## Compare OpenAI models

- [GPT Chat Latest vs GPT-3.5 Turbo](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-3.5-turbo>); [Markdown comparison](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-3.5-turbo.md>)
- [GPT Chat Latest vs GPT-4 Turbo](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4-turbo>); [Markdown comparison](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4-turbo.md>)
- [GPT Chat Latest vs GPT-4.1](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4.1>); [Markdown comparison](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4.1.md>)
- [GPT Chat Latest vs GPT-4.1 mini](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4.1-mini>); [Markdown comparison](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4.1-mini.md>)
- [GPT Chat Latest vs GPT-4.1 nano](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4.1-nano>); [Markdown comparison](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4.1-nano.md>)
- [GPT Chat Latest vs GPT-4o](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4o>); [Markdown comparison](<https://impossibl.com/compare/openai/chat-latest/openai/gpt-4o.md>)

## Frequently asked questions

### Which OpenAI models are available through Impossibl?

The directory lists 41 models from OpenAI available through the Impossibl API, including GPT Chat Latest, GPT-3.5 Turbo, and GPT-4 Turbo. Open each model page for its API identifier, capabilities, and current pricing.

### How much do OpenAI models cost?

OpenAI model prices vary by model and usage. All rates below are published base API rates in USD. For token-priced models, published input rates start at $0.02 per million input tokens. Published output rates start at $0.30 per million output tokens. Input and output minima may refer to different models. For audio-duration models, published input rates start at $0.0045 per minute of audio. Long-context tiers can change prices for the whole request; check each model's thresholds and rates. Individual model pages include published cache prices and billing units. Applicable fees and workspace-specific pricing can affect the amount paid.

### What context windows do OpenAI models support?

Among OpenAI models with a published limit on Impossibl, the largest context window is 1,050,000 tokens, listed for GPT-5.4, GPT-5.4 Pro, and GPT-5.5. Context limits vary by model and are separate from maximum output limits. Context windows are unpublished for 1 model.

### What inputs and capabilities do OpenAI models support?

Available model types include embeddings, image generation, speech to text, and text generation. Published input support includes audio, image, and text; support varies by model. Tool-calling support is unspecified for 41 models.

### How do I use OpenAI models through an API?

Use the exact model identifier from the model page with the Impossibl API. For example, select openai/chat-latest with /v1/chat/completions. Endpoint compatibility depends on the selected model. The API quickstart explains how to create an API key and send a request.

## Sources and related links

Prices, capabilities, limits, and availability describe the public Impossibl API offering. An unpublished fact is unknown; a published zero price is zero. Compare matching billing units and check context tiers before estimating costs.

- [Public Impossibl model catalog](<https://api.impossibl.com/v1/models>)
- [Full model directory as JSON](<https://impossibl.com/models.json>)
- [Model directory as Markdown](<https://impossibl.com/models.md>)
- [API quickstart](<https://impossibl.com/docs/agent-quickstart>)
- [Model documentation](<https://impossibl.com/docs/models>)