# 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.

- Model identifier: ` openai/gpt-3.5-turbo `
- Creator: OpenAI
- Model type: Text generation
- Canonical model page: [GPT-3.5 Turbo](<https://impossibl.com/openai/gpt-3.5-turbo>)
- API availability: Listed as serving through Impossibl.
- Creator release date: 2023-03-01

## Capabilities and limits

- Context window: 16,000 tokens
- Maximum output tokens: Not published in the public catalog; this is separate from the context window.
- Inputs: text
- Outputs: text
- Tool calling: Not published

## API access

Use ` openai/gpt-3.5-turbo ` as the model identifier through the Impossibl API.

Published API endpoints:

- ` /v1/chat/completions `

[API quickstart](<https://impossibl.com/docs/agent-quickstart>) · [Models and billing documentation](<https://impossibl.com/docs/models>)

## Published API prices

All rates are in USD. An unpublished rate is unknown, not zero. Workspace-specific pricing, taxes, balance-purchase fees, billing adjustments, and tool charges can affect the amount paid.

| Usage | Published base rate | Billing unit |
| --- | --- | --- |
| Input | $0.50 | per million input tokens |
| Output | $1.50 | per million output tokens |
| Cache read | Not published | per million cached input tokens |
| Cache write (default retention) | Not published | per million tokens |
| Cache write (one-hour retention) | Not published | per million tokens |
| Audio input | Not published | per million audio input tokens |

## Independent benchmarks

Source: [Artificial Analysis](<https://artificialanalysis.ai/>). Last checked: 2026-09-11T10:50:14.034Z.
Configurations are evaluated separately. API scores retain their original units. Unmeasured scores are omitted.

### GPT-3.5 Turbo

Source: [Evaluation source](<https://artificialanalysis.ai/models/gpt-35-turbo>)

| Benchmark | Score |
| --- | --- |
| Intelligence Index | 5.49 |
| GPQA | 29.70% |
| coding index (API) | 10.7 |
| intelligence index (API) | 5.5 |

Full benchmark data and breakdowns: [Complete benchmark snapshot](<https://api.impossibl.com/v1/models/openai/gpt-3.5-turbo/benchmarks>).


## Availability and retirement

The model is listed as serving. No retirement is announced in the current public catalog.

## Frequently asked questions

### What is GPT-3.5 Turbo?

GPT-3.5 Turbo is a text-generation model from OpenAI, available through the Impossibl API.

### How much does GPT-3.5 Turbo cost?

GPT-3.5 Turbo costs $0.50 per million input tokens and $1.50 per million output tokens through the Impossibl API. All rates are in USD.

### What is the context length of GPT-3.5 Turbo?

GPT-3.5 Turbo has a 16,000-token context window through the Impossibl API.

### What inputs and outputs does GPT-3.5 Turbo support?

GPT-3.5 Turbo accepts text as input. GPT-3.5 Turbo returns text.

### How do I use GPT-3.5 Turbo through an API?

GPT-3.5 Turbo is available through the Impossibl API. Use openai/gpt-3.5-turbo as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

### When was GPT-3.5 Turbo released?

OpenAI released GPT-3.5 Turbo on March 1, 2023.

Sources: [Creator release announcement](<https://community.openai.com/t/introducing-chatgpt-and-whisper-apis/80485>)

## Sources and related links

Prices, limits, capabilities, endpoints, and availability come from the public Impossibl catalog. Creator documentation supplies descriptions and release dates where available; it does not override the published API offering.

- [Public Impossibl model catalog](<https://api.impossibl.com/v1/models>)
- [Full model directory as JSON](<https://impossibl.com/models.json>)
- [GPT-3.5 Turbo: model details and pricing](<https://impossibl.com/openai/gpt-3.5-turbo>)
- [Model directory](<https://impossibl.com/models>)