SI Index Data as of Oct 9, 2026

Claude Opus 4.1: Price, Context, Benchmarks, and Release Details

Anthropic provisional listing · first seen Oct 8, 2026 · score computed Oct 9, 2026, 01:09 UTC
51.5
SI Score (method si-v3-retained-evidence-2)
#101 of 140 ranked
80% confidence 80 percent, High confidence — 3 of 7 expected sources in
Coverage 64% of expected source weight · 100% confidence at 80% coverage

Pillar breakdown

Coding (weight 40 percent) 73.3
Math (weight 15 percent) 17.6
Preference (weight 15 percent) 74.9
Reasoning (weight 30 percent) 30.5

Pillar weights: reasoning 30% · math 15% · coding 40% · preference 15%. Benchmark results use fixed 0–100 scales before averaging; incomplete evidence is shrunk toward 50.

Facts

Input price / 1M
not yet reported
Output price / 1M
not yet reported
Context window
200Kmodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
Max output
32Kmodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
Released
Aug 5, 2025models.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
Open weights
Nomodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗
License
not yet reported
Input modalities
text, image, pdfmodels.devPublished source fact Retrieved Oct 9, 2026 · MIT
Open source ↗

Benchmark results

11 results
Benchmark Raw result Normalized (0–100) Pillar
frontiermath tier 4 v2 2.4%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] 32KPublished Jun 11, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		2.4 math
frontiermath tiers 1 3 v2 12.6%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] 32KPublished Jun 11, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		12.6 math
gpqa diamond 73.2%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Aug 5, 2025 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		73.2 reasoning
gpqa diamond 77.3%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] 16KPublished Aug 5, 2025 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		77.3 reasoning
gpqa diamond 76.8%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] 27KPublished Aug 5, 2025 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		76.8 reasoning
hle scale 7.9%Humanity’s Last ExamPotential contamination warning: This model was evaluated after the public release of HLE, allowing model builder access to the prompts and solutions. [variant] Published Aug 8, 2025 Retrieved Oct 9, 2026 · factual citation
Open source ↗ 		7.9 reasoning
lmarena text 1418.6 eloLMArena / ArenaPublished source fact [variant] text / overallPublished Oct 2, 2026 Retrieved Oct 9, 2026 · CC-BY-4.0
Open source ↗ 		74.9 preference
otis mock aime 2024 2025 40%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Aug 5, 2025 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		40.0 math
otis mock aime 2024 2025 64.4%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] 16KPublished Aug 5, 2025 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		64.4 math
otis mock aime 2024 2025 68.9%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] 27KPublished Aug 5, 2025 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		68.9 math
swe bench verified 73.3%Epoch AI BenchmarkingEpoch-owned evaluation mean score; scores only, no benchmark questions [variant] Published Feb 11, 2026 Retrieved Oct 9, 2026 · CC-BY
Open source ↗ 		73.3 coding

Normalization uses fixed absolute 0–100 scales for each unit, independently of other models that have a result on each benchmark. Coverage and evidence breadth still affect the composite; compare the evaluation conditions before reading a small score gap as decisive. “lab-reported” marks the provider's own published figure.

Sources: in and pending

in Reported (3)

  • Epoch AI Benchmarking · arrived Oct 8, 2026
  • Humanity’s Last Exam · arrived Oct 8, 2026
  • LMArena / Arena · arrived Oct 8, 2026

pending Awaiting (4)

  • ARC Prize · carries 13% of expected weight
  • Official model cards via models.dev · carries 4% of expected weight
  • LiveBench · carries 13% of expected weight
  • Terminal-Bench · carries 6% of expected weight

The confidence % rises as pending sources publish. Some sources never cover some models — that is why 100% confidence arrives at 80% of expected weight, not at full coverage.