Claude Sonnet 4.6 (Adaptive Reasoning, Max Effort)
Claude Sonnet 4.6 (Adaptive Reasoning, Max Effort) is an API model from Anthropic. It’s positioned for general text tasks—work that benefits from iteration, not just one-shot answers.
Intelligence
Top 5%
Speed
Slow
58 tok/s output
Cost
High
$3.75 in / $15.00 out
Context
1M
Up to 1,000,000 tokens
How are Intelligence, Speed & Cost bucketed?
Intelligence and Speed buckets are percentile ranks on
Artificial Analysis. Cost buckets are fixed dollar
thresholds keyed off output-token price ($/M out).
Intelligence
- Top 1%≤ 1%
- Top 5%≤ 5%
- Top 10%≤ 10%
- Good≤ 25%
- Medium≤ 50%
- Below avg> 50%
Speed
- Top 1%≥ 345 tok/s
- Top 5%≥ 237 tok/s
- Top 10%≥ 196 tok/s
- Good≥ 146 tok/s
- Medium≥ 90 tok/s
- Slow< 90 tok/s
Cost
- Freeopen weights · self-host
- Low< $1 / M out
- Moderate$1–5 / M out
- High≥ $5 / M out
Core Capabilities
Long Documents
Handles entire codebases, books, and multi-doc RAG.
Context Window
1M tokens
≈ entire codebase
4k Chat 聊天
32k Long docs 长文档
128k Books 整本书
400k Multi-doc 多文档
1M This model 本模型
10M
Availability
API
Available
Product / App
Not available
Open Source
Not released
Enterprise
Contact sales
Pricing Model
Pay per token
Input and output billed separately.
Pay-per-token Capability / Performance
Where this model sits relative to the middle 60% of models in the tree. All scores are 0–10 (higher is better).
Lower 20% Upper 80% This model
Context / memory
Context window size · log-scaled
6.0
9.0
9.0
Lower 20% 20th percentile — 20% of models score below this This model Where the current model lands Upper 80% 80th percentile — only 20% of models score above this
Percentile boundaries are computed across every model in the tree that reports the underlying benchmark for each capability.
What it feels like
- Topped SWE-bench Verified at release — Cognition reported 18% planning gain and 12% end-to-end eval gain for Devin
- Edit accuracy is the headline change — internal code-editing error rate dropped from 9% on Sonnet 4 to 0%
- Sustains 30+ hour autonomous coding focus without losing the thread
Best use cases
- Production agentic coding (Devin, Cursor, Cline) where reliability matters
- AI SRE / on-call automation with long task horizons
- Day-to-day software engineering at scale on real GitHub issues
Tools to try
Not ideal for
- The very hardest reasoning tasks — Opus 4.5 still leads by ~7 points on AA Intelligence Index
- Simple chat or casual Q&A — try Haiku 4.5 instead
Model Evolution
claude-sonnet is Anthropic's language model family.
Claude Sonnet 4.5
Sep 2025
Claude Sonnet 4.6
Nov 2025
Claude Sonnet 4.6 (Adaptive Reasoning, Max Effort)
Jan 2026