Anthropic · frontier · Released 2026-03-08

Claude Sonnet 4.5 Max: pricing, context window and benchmarks

Claude Sonnet 4.5 Max is a frontier model from Anthropic. It offers a 1,000,000-token context window, costs $19.90 per million input tokens and $95.47 per million output tokens, and averages 87.2 across the index's benchmark suite.

frontierreasoningcodingvisionlong contextmultimodal
Input price
$19.90
per 1M tokens
Output price
$95.47
per 1M tokens
Context
1,000,000
tokens
Avg score
87.2
rank #21 of 600
Arena Elo
1474.9
modelled
Max output
65,536
tokens

Pricing

Claude Sonnet 4.5 Max costs $19.90 per million input tokens and $95.47 per million output tokens. A blended 3:1 input-to-output mix works out to about $38.79 per million tokens. Cached input is listed at $2.63 per million tokens.

ItemPriceNotes
Input$19.90per 1M tokens
Output$95.47per 1M tokens
Cached input$2.63per 1M tokens
Blended 3:1$38.79estimate per 1M tokens
1M in + 1M out$115.37estimate

Benchmarks

Scores below are modelled estimates on a 0–100 scale. Use them to compare relative position, not as official vendor results.

BenchmarkScoreRankPercentileRelative
MMLU-Pro 86.1 50 92th
GPQA Diamond 84.4 10 98th
SWE-bench Verified 80.2 4 99th
HumanEval 92.4 16 97th
MATH-500 92.8 13 98th
AIME 2025 85.4 33 95th
LiveCodeBench 82.8 15 98th
IFEval 92.9 21 97th
TruthfulQA 87.3 30 95th
HellaSwag 93.1 20 97th
MMMU 82.0 32 95th
Arena Elo 1474.9 26 96th

What Claude Sonnet 4.5 Max is good for

Claude Sonnet 4.5 Max sits in the frontier tier of the index. It is aimed at work where answer quality matters more than unit cost: hard reasoning, multi-step coding, document analysis and multimodal inputs. At $19.90 per million input tokens and a 1,000,000-token context window, it is a premium option, so reserve it for tasks where a cheaper model measurably fails.

Strengths

  • Top-tier average benchmark score (87.2), placing it #21 of 600.
  • Large 1,000,000-token context window for long documents and agent traces.
  • Accepts more than text, including image input where the provider supports it.
  • Reasoning-oriented profile, useful for multi-step problems and structured analysis.
  • Coding benchmarks are a relative strength within its tier.

Trade-offs

  • Proprietary licence: you cannot download the weights or self-host the model.
  • Premium input pricing at $19.90 per million tokens.
  • Cost can climb quickly on long outputs and high-volume traffic.

How it compares

ModelProviderContextInput / 1MAvg score
GPT-5.2 Reasoning OpenAI 1000000 $20.98 87.5
GPT-5.2 Turbo OpenAI 1000000 $20.73 87.4
GPT-5.2 Vision OpenAI 1000000 $19.03 87.4
Gemini 3 Pro Pro Google DeepMind 200000 $19.80 87.3
o4 Pro OpenAI 1000000 $19.37 87.3
Claude Sonnet 4.5 Max Anthropic 1000000 $19.90 87.2

Browse all comparisons →

FAQ

How much does Claude Sonnet 4.5 Max cost?

Claude Sonnet 4.5 Max is listed at $19.90 per million input tokens and $95.47 per million output tokens. Cached input is $2.63 per million tokens. A blended 3:1 input-to-output mix is about $38.79 per million tokens.

What is the context window of Claude Sonnet 4.5 Max?

Claude Sonnet 4.5 Max has a context window of 1,000,000 tokens and can emit up to 65,536 output tokens per request in this index.

Is Claude Sonnet 4.5 Max open weights?

No. Claude Sonnet 4.5 Max is a proprietary model with a proprietary licence, so you cannot download the weights.

How does Claude Sonnet 4.5 Max score on benchmarks?

Claude Sonnet 4.5 Max averages 87.2 across the scored benchmarks in this index, ranking #21 of 600 models. Its strongest relative result is Arena Elo at 1474.9.

What is Claude Sonnet 4.5 Max best for?

Claude Sonnet 4.5 Max sits in the frontier tier of the index. It is aimed at work where answer quality matters more than unit cost: hard reasoning, multi-step coding, document analysis and multimodal inputs. At $19.90 per million input tokens and a 1,000,000-token context window, it is a premium option, so reserve it for tasks where a cheaper model measurably fails.

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