Anthropic · Efficient
Claude Haiku 4.5 Thinking
Claude Haiku 4.5 with extended thinking enabled for deeper planning, more deliberate coding, and multi-step reasoning without moving up to Sonnet pricing.
- Reasoning
- Tools
- Vision
- Structured output
- PDF input
- Input
- Text, Images
- Output
- Text
- Discovery tier
- Efficient
Pricing
USD per 1M tokens- Input
- $1.00
- Output
- $5.00
- Cache read
- $0.10
Reference prices as published by the model provider. API example
Specifications
- Context window
- 200K
- Max output
- 64K
Side by side
Claude Haiku 4.5 Thinking compared
Specifications, prices, speed and benchmark scores next to each other. Benchmarks below show every compared model too.
| Claude Haiku 4.5 ThinkingAnthropicThis model | Claude Haiku 5.5AnthropicRemove | |
|---|---|---|
| Provider | Anthropic | Anthropic |
| Discovery tier | Efficient | Efficient |
| Added | Oct 15, 2025 | Oct 7, 2026 |
| Limits | ||
| Context window | 200K | 1MBest |
| Max output | 64K | 128KBest |
| Average output | — | 1.5K tokens |
| Pricing, USD per 1M tokens | ||
| Input | $1.00 | $0.10Best |
| Output | $5.00 | $0.50Best |
| Cache read | $0.10 | $0.01Best |
| Cache write | — | $0.13 |
| Performance | ||
| Throughput | — | 308.9 tok/s |
| Time to first token | — | 3.1 s |
| Request success (24h) | 97.0% | 99.9%Best |
| Benchmark indexes | ||
| Intelligence Index | — | 43.4 |
| Capabilities | ||
| Reasoning | Yes | Yes |
| Tools | Yes | Yes |
| Vision | Yes | Yes |
| Structured output | Yes | Yes |
| PDF input | Yes | Yes |
| Reasoning effort | — | low, medium, high, xhigh, max |
Public evaluations
Benchmarks
Independent evaluation results, with how each score ranks among the models in the Noumen catalog.
- Claude Haiku 4.5 Thinking
- Claude Haiku 5.5
Intelligence Index
- Claude Haiku 4.5 Thinking—
- Claude Haiku 5.543.4
Agentic work
AutomationBench-AA
Workflow automation, penalized for guardrail violations
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 35.4%
AutomationBench-AA tasks completed
Workflows finished end to end without a guardrail violation
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 13.9%
Harvey LAB-AAv1.1
Legal tasks passed in full, with no material hallucination
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 0.6%
AA-Briefcasev1.1
Agentic knowledge work, rated head to head
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 1,575 Elo
GDPval-AAv2.1
Economically valuable occupational tasks, rated head to head
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 1,619 Elo
Document reasoning
GDP.pdf
Professional reasoning over PDF documents, all-pass rate
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 20.8%
AA-LCRv1.1
Reasoning across long documents
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 82.7%
MLCR-AA
Long-context reasoning over medical records
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 35.0%
Reasoning and knowledge
Humanity’s Last Exam
Expert-level questions across academic fields
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 44.4%
Coding
Terminal-Benchv4.0
Practical software engineering in a terminal
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 32.8%
SciCode
Scientific computing in Python
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 55.0%
Legacy evaluations
AA-LCR (unversioned)
Long-context reasoning, earlier grading
- Claude Haiku 4.5 Thinking: —
- Claude Haiku 5.5: 82.7%
Scores from Artificial Analysis, updated Oct 26, 2026. Artificial Analysis
- Claude Haiku 4.5 Thinking
- Claude Haiku 5.5
| Leaderboard | Claude Haiku 4.5 Thinking | Claude Haiku 5.5 |
|---|---|---|
| FrontierCode Main | Not in top 20 | #14 · 46.4% |
| FrontierCode Extended | Not in top 20 | #14 · 58.4% |
Ranks among Noumen catalog models on FrontierCode leaderboards. Only top-20 placements are listed.FrontierCode
- Claude Haiku 4.5 Thinking
- Claude Haiku 5.5
| Leaderboard | Claude Haiku 4.5 Thinking | Claude Haiku 5.5 |
|---|---|---|
| Epoch Capabilities Index | Not in top 20 | #15 · 159.3 |
Ranks among Noumen catalog models on Epoch AI leaderboards. Only top-20 placements are listed.Epoch AI
- Claude Haiku 4.5 Thinking
- Claude Haiku 5.5
| Leaderboard | Claude Haiku 4.5 Thinking | Claude Haiku 5.5 |
|---|---|---|
| ARC-AGI-3 (Default harness) | Not in top 20 | #13 · 0.5% |
Ranks among Noumen catalog models on ARC Prize leaderboards. Only top-20 placements are listed.ARC Prize
- Claude Haiku 4.5 Thinking
- Claude Haiku 5.5
| Leaderboard | Claude Haiku 4.5 Thinking | Claude Haiku 5.5 |
|---|---|---|
| Game Development | Not in top 20 | #15 · 1325 |
| Data Visualization | Not in top 20 | #15 · 1294 |
| 3D | Not in top 20 | #14 · 1344 |
Ranks among Noumen catalog models on Design Arena leaderboards. Only top-20 placements are listed.Design Arena
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.
- Prompt cache hits
- 88.5%
- About $0.20 per 1M input tokens with caching
- Request success (24h)
- 97.0%
- 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.
- 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.
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-4.5:thinking",
"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-4.5:thinking",
messages=[{"role": "user", "content": "Explain this stack trace."}],
)
print(reply.choices[0].message.content)Anthropic
Related models
Other Anthropic models, starting with the same family.