# Claude Opus 4.1

Claude Opus 4.1 is an AI model released by Anthropic on Aug 5 2025. At release it scored 43% on BullshitBench v2, 80.9% on GPQA Diamond and 74.5% on SWE-Bench Verified.

## Facts

| Field | Value |
| --- | --- |
| Model | Claude Opus 4.1 |
| Developer | Anthropic |
| Release date | Tuesday, Aug 5 2025 |
| Licensing | Proprietary |

## Benchmark scores published at release

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| BullshitBench v2 | 43% | [BullshitBench](https://github.com/petergpt/bullshit-benchmark) | Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. |
| SWE-Bench Verified | 74.5% | Lab | Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. |
| GPQA Diamond | 80.9% | Lab | Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. |

## Questions and answers

### When was Claude Opus 4.1 released?

Claude Opus 4.1 was released by Anthropic on Tuesday, Aug 5 2025.

### Who made Claude Opus 4.1?

Claude Opus 4.1 was built by Anthropic. AI safety company building the Claude family of models. Founded in 2021 by former OpenAI researchers.

### What benchmark scores did Claude Opus 4.1 get?

Claude Opus 4.1 reports 3 tracked benchmark scores — BullshitBench v2: 43%; SWE-Bench Verified: 74.5%; GPQA Diamond: 80.9%. Scores are the figures published at release by Anthropic.

### Is Claude Opus 4.1 open source?

No. Claude Opus 4.1 is a proprietary model. The weights are not published — it is available only through the provider's own API, apps, or partner platforms.

### What came before and after Claude Opus 4.1?

Anthropic's previous tracked release was Claude Opus 4 on May 22 2025, 75 days earlier. It was followed by Claude Sonnet 4.5 on Sep 29 2025.


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Canonical page: https://aireleasetracker.com/model/anthropic/claude-opus-4.1
Full dataset: https://aireleasetracker.com/llms-full.txt · JSON: https://aireleasetracker.com/models.json
Source: AI Release Tracker (https://aireleasetracker.com). Most benchmark scores come from lab launch material; gathered results identify the leaderboard that published them.