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Claude Haiku 4.5

Parameters

-

Context Length

200K

Modality

Text

Architecture

Dense

License

Proprietary

Release Date

1 Oct 2025

Knowledge Cutoff

Feb 2025

Technical Specifications

Attention Structure

Multi-Head Attention

Hidden Dimension Size

-

Number of Layers

-

Attention Heads

-

Key-Value Heads

-

Activation Function

-

Normalization

-

Position Embedding

Absolute Position Embedding

Claude Haiku 4.5

Claude Haiku 4.5 is a high-throughput, multimodal large language model designed for low-latency applications requiring near-frontier intelligence at scale. Within the Claude 4.5 model family, Haiku serves as the optimized execution engine, balancing computational efficiency with sophisticated capabilities such as agentic reasoning and autonomous computer use. It is engineered to handle complex, multi-step instructions and high-volume data streams, making it a primary choice for developers building responsive AI agents and real-time customer-facing services.

Technically, the model utilizes a dense transformer architecture and is trained with a specialized focus on context awareness. This architectural refinement allows the model to monitor its own token consumption within its 200,000-token context window, effectively mitigating agentic laziness and ensuring persistent reasoning during long-running tasks. Unlike many contemporary models that employ rotary embeddings, Claude 4.5 Haiku continues to utilize absolute position embeddings combined with multi-head attention (MHA) to maintain structural consistency and precision across its expanded context. The model supports multimodal inputs, enabling it to process and analyze visual data alongside text with significant speed.

Performance characteristics are centered on rapid inference and cost-effectiveness for production-grade workloads. A standout feature of this variant is the inclusion of extended thinking, which allows the model to allocate additional internal compute for deliberate reasoning before generating an output. This makes Haiku 4.5 particularly effective for sub-agent orchestration, where it acts as a fast executor for plans developed by larger models like Sonnet 4.5. Common use cases include automated financial monitoring, real-time code refactoring, and large-scale document processing where maintaining high quality at a reduced cost is a technical requirement.

About Claude 4.5

Enhanced Claude models with further improvements in reasoning, coding, and agentic capabilities. Features advanced thinking modes with adjustable effort levels (high, medium, standard) for optimal performance-latency tradeoffs. Excels at complex analysis, software development, web development, and long-context understanding. Includes thinking variants that expose reasoning process for improved transparency.


Other Claude 4.5 Models

Evaluation Benchmarks

Rank

#69

BenchmarkScoreRank

Web Development

WebDev Arena

1405

17

0.72

22

Agentic Coding

LiveBench Agentic

0.33

25

0.66

35

0.34

40

0.58

42

Rankings

Overall Rank

#69

Coding Rank

#21

Claude Haiku 4.5: Model Specifications and Details