# Claude Haiku 4.5

Claude Haiku 4.5 is a text generation model from Anthropic, available through the Impossibl API. Its published context window is 200,000 tokens. The advertised input rate is $1.00 per million input tokens. The advertised output rate is $5.00 per million output tokens.

- Model identifier: ` anthropic/claude-haiku-4-5 `
- Creator: Anthropic
- Model type: Text generation
- Canonical model page: [Claude Haiku 4.5](<https://impossibl.com/anthropic/claude-haiku-4-5>)
- API availability: Listed as serving through Impossibl.
- Creator release date: 2025-10-15

## Capabilities and limits

- Context window: 200,000 tokens
- Maximum output tokens: Not published in the public catalog; this is separate from the context window.
- Inputs: text, image
- Outputs: text
- Tool calling: Not published

## API access

Use ` anthropic/claude-haiku-4-5 ` 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 An unpublished rate is unknown, not zero.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 | $1.00 | per million input tokens |
| Output | $5.00 | per million output tokens |
| Cache read | $0.10 | per million cached input tokens |
| Cache write (default retention) | $1.25 | per million tokens |
| Cache write (one-hour retention) | $2.00 | 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.

### Claude 4.5 Haiku (Non-reasoning)

Source: [Evaluation source](<https://artificialanalysis.ai/models/claude-4-5-haiku>)

| Benchmark | Score |
| --- | --- |
| Intelligence Index | 15.41 |
| Omniscience Index | -7.57 |
| GPQA | 64.65% |
| Humanity’s Last Exam | 4.22% |
| CritPt | 0.00% |
| Terminal-Bench Hard | 27.27% |
| AA-LCR | 49.67% |
| Multilingual LCR | 4.44% |
| MMMU-Pro | 55.14% |
| IFBench | 42.04% |
| Tau2 | 32.46% |
| LiveCodeBench | 51.11% |
| AIME 2025 | 39.00% |
| intelligence index (API) | 15.4 |

### Claude 4.5 Haiku (Reasoning)

Source: [Evaluation source](<https://artificialanalysis.ai/models/claude-4-5-haiku-reasoning>)

| Benchmark | Score |
| --- | --- |
| Intelligence Index | 17.59 |
| Omniscience Index | -4.37 |
| GPQA | 67.17% |
| Humanity’s Last Exam | 10.38% |
| SciCode | 42.25% |
| CritPt | 0.00% |
| Terminal-Bench v2.1 | 44.19% |
| Terminal-Bench v4.0 | 0.00% |
| Terminal-Bench Hard | 27.27% |
| AA-LCR | 74.33% |
| Multilingual LCR | 6.11% |
| Harvey LAB | 61.05% |
| GDPval Elo | 854.45 |
| GDP.pdf All-pass | 3.80% |
| AutomationBench Partial | 3.25% |
| AnalystAgent | 15.00% |
| MMMU-Pro | 58.55% |
| IFBench | 54.29% |
| Tau2 | 54.68% |
| Tau Banking | 9.28% |
| ITBench | 27.31% |
| LiveCodeBench | 61.48% |
| AIME 2025 | 83.67% |
| coding index (API) | 43.9 |
| agentic index (API) | 10.3 |
| intelligence index (API) | 17.6 |

Full benchmark data and breakdowns: [Complete benchmark snapshot](<https://api.impossibl.com/v1/models/anthropic/claude-haiku-4-5/benchmarks>).


## Availability and retirement

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

## Frequently asked questions

### What is Claude Haiku 4.5?

Claude Haiku 4.5 is a text-generation model from Anthropic, available through the Impossibl API.

### How much does Claude Haiku 4.5 cost?

Claude Haiku 4.5 costs $1.00 per million input tokens and $5.00 per million output tokens through the Impossibl API. Cache reads cost $0.10 per million tokens; cache writes cost $1.25 per million tokens; cache writes with one-hour retention cost $2.00 per million tokens. All rates are in USD.

### What is the context length of Claude Haiku 4.5?

Claude Haiku 4.5 has a 200,000-token context window through the Impossibl API.

### What inputs and outputs does Claude Haiku 4.5 support?

Claude Haiku 4.5 accepts text and image as input. Claude Haiku 4.5 returns text.

### How do I use Claude Haiku 4.5 through an API?

Claude Haiku 4.5 is available through the Impossibl API. Use anthropic/claude-haiku-4-5 as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

### When was Claude Haiku 4.5 released?

Anthropic released Claude Haiku 4.5 on October 15, 2025.

Sources: [Creator release announcement](<https://www.anthropic.com/news/claude-haiku-4-5>)

## 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>)
- [Claude Haiku 4.5: model details and pricing](<https://impossibl.com/anthropic/claude-haiku-4-5>)
- [Model directory](<https://impossibl.com/models>)