The Model Index
Models/Anthropic

Claude Opus 4.1

AnthropicReleased 5 Aug 2025ClosedFlagshipDate verified
140129–152Index score#87 of 229 models
6/ 8Core tests taken4 of 6 areas · plus 14 anchor tests
−6Versus the frontier at releasebest then: o3Replaced by Claude Opus 4.5
$15/ $75Price per million tokensinput / output, list price
200KContext windowtokens it reads at once

Where it sitson the frontier

Gemini 2.5 Pro reached this score 4 months earlier.

Test resultsby area · tick = best by any model

Reasoning & knowledgeevidence
GPQA Diamond
77%
Humanity's Last Exam
12%
Mathsevidence
FrontierMath T1-3
13%
Codingevidence
SWE-bench Verified
73%
Terminal-Bench
38%
Agentsevidence
APEX-Agents
no result
Novel problemsno evidence yet
ARC-AGI-2
no result
Long tasksevidence
METR time horizon
1.9 h

Independent results from the Epoch AI benchmarking hub, best reasoning setting. The core tests are shown here; anchor tests also inform the score and can be shown above.

What others sayrank on each leaderboard

The Model Indexindependent tests, our method#87of 219 · 140
Epoch Capabilities Indexoverall capability from many benchmarks#84of 239 · 144.1

Further left is better. Leaderboards measure different things: LMArena is people voting blind between two answers, the others are test scores. Click any row for the source.

Best attop three among current models

Where this model places in the top three of today's models, on category leaderboards and on our core tests.

Where to use itprices checked 1 Oct 2026

API providers 1 · per million tokens, in / out

AAmazon Bedrock$15 / $75cheapest

Provider prices come from OpenRouter's live listing; going direct to a provider can differ. Subscriptions are the lab's own apps.

Facts and sources

Released5 Aug 2025
Announcementanthropic.com ↗
Release entryClaude Opus 4.1
Scored asClaude Opus 4.1
Artificial Analysis index–
Output speed–
Hugging Faceclosed weights

Anthropic releasesaround this one