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Anthropic · Efficient

Claude Haiku 5.5

Added Oct 7, 2026

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Use in the app

Claude Haiku 5.5 is Anthropic's fastest and most capable small model, designed for high-volume, cost-sensitive tasks such as summaries, classification, coding assistance, and live customer support. It delivers major gains over Haiku 4.5 while costing around 75% less to run.

  • Reasoning
  • Tools
  • Vision
  • Structured output
  • PDF input
Input
Text, Images
Output
Text
Reasoning effort
low · medium · high · xhigh · max
Discovery tier
Efficient

Pricing

USD per 1M tokens
Input
$0.10
Output
$0.50
Cache read
$0.01
Cache write
$0.13
$0.20 for a 1-hour cache

Reference prices as published by the model provider. API example

Specifications

Context window
1M
Max output
128K
Average output (7 days)
1.5K tokens
Longer than 86% of 465 models

Side by side

Claude Haiku 5.5 compared

Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.

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Claude Haiku 5.5AnthropicThis modelClaude Opus 5.5AnthropicRemove
ProviderAnthropicAnthropic
Discovery tierEfficientFrontier
AddedOct 7, 2026Sep 22, 2026
Limits
Context window1M1M
Max output128K128K
Average output1.5K tokens2K tokens
Pricing, USD per 1M tokens
Input$0.10Best$4.00
Output$0.50Best$20.00
Cache read$0.01Best$0.20
Cache write$0.13Best$5.00
Performance
Throughput308.9 tok/sBest191.9 tok/s
Time to first token3.1 sBest5.8 s
Request success (24h)99.9%Best99.8%
Benchmark indexes
Intelligence Index43.453.6Best
Capabilities
ReasoningYesYes
ToolsYesYes
VisionYesYes
Structured outputYesYes
PDF inputYesYes
Reasoning effortlow, medium, high, xhigh, maxlow, medium, high, xhigh, max

Public evaluations

Benchmarks

Independent evaluation results, with how each score ranks among the models in the Noumen catalog.

  • Claude Haiku 5.5
  • Claude Opus 5.5

Intelligence Index

  • Claude Haiku 5.543.4
  • Claude Opus 5.553.6

Claude Haiku 5.5 tested at max reasoning effort

Claude Haiku 5.5: Better than 88% of 326 scored models

3.8Catalog models by score55.1

Agentic work

  • AutomationBench-AA

    Workflow automation, penalized for guardrail violations

    • Claude Haiku 5.5: 35.4%
    • Claude Opus 5.5: 63.2%Top

  • AutomationBench-AA tasks completed

    Workflows finished end to end without a guardrail violation

    • Claude Haiku 5.5: 13.9%
    • Claude Opus 5.5: 33.8%Top

  • Harvey LAB-AAv1.1

    Legal tasks passed in full, with no material hallucination

    • Claude Haiku 5.5: 0.6%
    • Claude Opus 5.5: —

  • AA-Briefcasev1.1

    Agentic knowledge work, rated head to head

    • Claude Haiku 5.5: 1,575 Elo
    • Claude Opus 5.5: 1,683 EloTop

  • GDPval-AAv2.1

    Economically valuable occupational tasks, rated head to head

    • Claude Haiku 5.5: 1,619 Elo
    • Claude Opus 5.5: 1,704 EloTop

Document reasoning

  • GDP.pdf

    Professional reasoning over PDF documents, all-pass rate

    • Claude Haiku 5.5: 20.8%
    • Claude Opus 5.5: 28.8%Top

  • AA-LCRv1.1

    Reasoning across long documents

    • Claude Haiku 5.5: 82.7%Top
    • Claude Opus 5.5: 82.7%Top

  • MLCR-AA

    Long-context reasoning over medical records

    • Claude Haiku 5.5: 35.0%Top
    • Claude Opus 5.5: 15.0%

Reasoning and knowledge

  • Humanity’s Last Exam

    Expert-level questions across academic fields

    • Claude Haiku 5.5: 44.4%
    • Claude Opus 5.5: 55.6%Top

Coding

  • Terminal-Benchv4.0

    Practical software engineering in a terminal

    • Claude Haiku 5.5: 32.8%
    • Claude Opus 5.5: 56.6%Top

  • SciCode

    Scientific computing in Python

    • Claude Haiku 5.5: 55.0%
    • Claude Opus 5.5: 60.4%Top

Legacy evaluations

  • AA-LCR (unversioned)

    Long-context reasoning, earlier grading

    • Claude Haiku 5.5: 82.7%Top
    • Claude Opus 5.5: 82.7%Top

Scores from Artificial Analysis, updated Oct 26, 2026. Claude Haiku 5.5 was tested at max reasoning effort; compare scores measured at the same effort.Artificial Analysis

Live routing data

Performance and reliability

Recent averages across requests routed for this model. Your own speed depends on prompt length, reasoning effort and load.

Throughput
308.9 tok/s
Faster than 94% of 250 models
Time to first token
3.1 s
Quicker than 55% of 250 models
Prompt cache hits
59.4%
About $0.0465 per 1M input tokens with caching
Request success (24h)
99.9%
Reliable

Cache hits are the share of input tokens recently served from a prompt cache across all requests. They are not a forecast of your own hit rate.

Hourly request success · last 72 hoursLowest hour 93.1%
  • Healthy (98% or more)
  • Degraded (90–98%)
  • Down (under 90%)
  • No requests

Developers

Use it through the API

Noumen’s API is OpenAI-compatible: any Chat Completions client works with a base URL and a key.

Read the quickstart
curl https://www.noumen.xyz/api/v1/chat/completions \
  -H "Authorization: Bearer $NOUMEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "anthropic/claude-haiku-5.5",
    "reasoning_effort": "medium",
    "messages": [{ "role": "user", "content": "Explain this stack trace." }]
  }'
import os
from openai import OpenAI

client = OpenAI(base_url="https://www.noumen.xyz/api/v1", api_key=os.environ["NOUMEN_API_KEY"])
reply = client.chat.completions.create(
    model="anthropic/claude-haiku-5.5",
    messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)

Anthropic

Other Anthropic models, starting with the same family.