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Claude Sonnet 5.5 benchmarks, pricing and specs

Claude Sonnet 5.5 is an Anthropic model released on September 28, 2026 that takes text and image input and produces text. It costs $2 per 1M input tokens and $10 per 1M output tokens and accepts up to 1,000,000 tokens of context. It scores 1476 Elo on Arena Text, #17 of 39 current models (Arena, measured October 8, 2026).

Per 1M input tokens
$2
Per 1M output tokens
$10
Context window
1M
Arena Text
1476 Elo · #17/39

Data verified October 12, 2026 · Dataset 2026-10-12

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Key facts

Provider
Anthropic
Model family
Claude Sonnet
Release date
September 28, 2026
Status
Current
Access
API only
API model id
Not reported
Context window
1,000,000 tokens
Max output
128,000 tokens
Input
text, image
Output
text
Task families
text, multimodal
Declared capabilities
reasoning

Claude Sonnet 5.5 pricing

It is the #12 most expensive of 37 current text models priced per 1M input tokens.

UnitPrice (USD)TierAppliesSource
1M input tokens$2standardCurrent
1M output tokens$10standardCurrent
1M input tokens$0.10cachedCurrent
1M input tokens$2.50cache write 5mCurrent
1M input tokens$4cache write 1hCurrent
1M input tokens$1batchCurrent
1M output tokens$5batchCurrent

Independent benchmark results

Scores come from independent evaluators that ran the model themselves, pinned to a dated snapshot. Rank is among current models in the same snapshot. Anthropic's own launch figures are listed under strengths with the publisher named, because they are not measured the same way.

BenchmarkScoreRankMeasuredSource
Arena Text1476 Elo#17 of 39October 8, 2026Arena · 2026-10-12
GPQA Diamond95.6%#2 of 37October 12, 2026Epoch AI · 2026-10-12
FrontierMath Tiers 1-3 (v2)88.8%#7 of 37October 12, 2026Epoch AI · 2026-10-12
SimpleQA Verified46.5%#21 of 34October 12, 2026Epoch AI · 2026-10-12

Strengths, cautions and best uses

Strengths

  • Anthropic's speed-and-intelligence tier at $2 per million input and $10 per million output, with the same 1M-token window and 128,000-token output cap as Opus 5.5
  • Cache reads at 0.05x base input ($0.10 per million), half the usual multiplier
  • Keeps the high effort default, unlike Claude Opus 5.5

Cautions

  • Same list price as Claude Sonnet 5, so the gain is capability and cache economics rather than a cheaper rate card
  • Anthropic positions Opus 5.5 rather than this as the default, so reach for Sonnet 5.5 when latency matters more than peak capability

Best for

  • Production workloads that need frontier-adjacent quality at a mid-tier rate
  • Latency-sensitive agent steps inside a larger pipeline

Alternatives to Claude Sonnet 5.5

The closest current textmodels by price. The cheapest model that scores as well or better is listed first; failing that, the cheapest one within 3% of the benchmark's scale.

Compare Claude Sonnet 5.5 with

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Claude Sonnet 5.5 FAQ

How much does Claude Sonnet 5.5 cost?

Claude Sonnet 5.5 costs $2 per 1M input tokens and $10 per 1M output tokens at the standard tier. It is the #12 most expensive of 37 current text models priced per 1M input tokens. Source: Anthropic, verified October 11, 2026.

What is the context window of Claude Sonnet 5.5?

Claude Sonnet 5.5 accepts up to 1,000,000 tokens of context. It can return up to 128,000 tokens in one response. That ranks #24 of 44 current text models by context length.

How does Claude Sonnet 5.5 score on independent benchmarks?

Claude Sonnet 5.5 scores 1476 Elo on Arena Text, #17 of 39 current models (Arena, measured October 8, 2026), 95.6% on GPQA Diamond, #2 of 37 current models (Epoch AI, measured October 12, 2026) and 88.8% on FrontierMath Tiers 1-3 (v2), #7 of 37 current models (Epoch AI, measured October 12, 2026). These are independent evaluations, not Anthropic's own launch figures.

Is Claude Sonnet 5.5 open source or API only?

Claude Sonnet 5.5 is available through Anthropic's API only; its weights are not published.

What are the best alternatives to Claude Sonnet 5.5?

The closest current alternatives by price and measured performance are Gemini 3.8 Flash (63% cheaper per 1M input tokens, $0.75 vs $2), GPT-4.1 (same price per 1M input tokens, $2), GPT-5.6 Terra (same price per 1M input tokens, $2) and Grok 4.5 (same price per 1M input tokens, $2).

Sources

Cite this page

Van Data Team. "Claude Sonnet 5.5 Benchmarks, Pricing and Specs." AI Model Benchmark Dataset 2026-10-12. https://vandatateam.com/ai-model-benchmarks/claude-sonnet-5-5

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Production evaluation

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