Claude Haiku 4

Anthropic Claude 4 Generally Available Oct 2025

Anthropic's fastest and most affordable Claude 4 model. Matches Sonnet on coding benchmarks at 3× lower cost and 2× the speed — ideal for real-time and agent workloads.

Context
200K
tokens
Input
$1.00
per MTok
Output
$5.00
per MTok

Modalities

Input
Text Vision Documents / PDFs Code
Output
Text Code

Code Examples

curl https://api.anthropic.com/v1/messages \
  -H "x-api-key: $ANTHROPIC_API_KEY" \
  -H "anthropic-version: 2023-06-01" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "claude-haiku-4-20251001",
    "max_tokens": 1024,
    "messages": [
      { "role": "user", "content": "Explain quantum entanglement in one sentence." }
    ]
  }'

API Parameters

Name Type Description
frequency_penalty number Penalize tokens by their frequency so far. Positive values reduce repetition.
max_completion_tokens integer Maximum number of tokens the model may generate in the response.
presence_penalty number Penalize tokens that have appeared at all so far. Positive values encourage new topics.
response_format one of Constrain output to a JSON schema or an enum (structured outputs).
seed integer Deterministic seed for sampling. Same seed + same prompt produces identical output.
stop array Up to 4 sequences where the API will stop generating tokens.
stream boolean Stream partial responses as Server-Sent Events.
temperature number Sampling temperature; higher values produce more random output. 0 is deterministic.
tool_choice one of Controls which (if any) tool is called: "none", "auto", "required", or a specific tool.
tools array List of tools (functions) the model may call.
top_p number Nucleus sampling: consider only tokens whose cumulative probability ≥ top_p.

Standard OpenAI-compatible parameters. Consult the provider docs for model-specific behaviour.

Benchmark Scores

Benchmark Score
MMLU 83%
SWE-bench Verified 73.3%
GPQA Diamond 63.2%

Performance

160
tok / sec
output speed

Source: Anthropic docs + llm-stats.com, April 2026

Strengths & Limitations

Best For
Best-in-class cost efficiency
Fast inference speed
Computer use + extended thinking
Great for multi-agent pipelines
Limitations
Slightly weaker reasoning than Sonnet
No audio modality

Tags

FastCheapCodingAgentTool Use