# Claude Opus 4

Claude Opus 4 is an AI model released by Anthropic on May 22 2025. Tracked results include 34% on BullshitBench v2, 79.6% on GPQA Diamond and 72.5% on SWE-Bench Verified.

## Facts

| Field | Value |
| --- | --- |
| Model | Claude Opus 4 |
| Developer | Anthropic |
| Release date | Thursday, May 22 2025 |
| Licensing | Closed |

## Tracked benchmark scores

| Benchmark | Score | Source | What it measures |
| --- | --- | --- | --- |
| BullshitBench v2 | 34% | [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 | 72.5% | 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 | 79.6% | Lab | Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. |

## About Claude Opus 4

Claude Opus 4 arrived May 22, 2025 together with Claude Sonnet 4, reviving the Opus tier after more than a year and marking Anthropic's pivot to long-horizon agentic work. It was pitched at sustained, multi-hour coding sessions — refactoring across large codebases, running in agent harnesses, and using tools in extended loops — rather than single-shot chat answers.

It posted 79.6% on GPQA Diamond and 72.5% on SWE-Bench Verified, roughly ten points above Claude 3.7 Sonnet on software engineering. Claude Opus 4.1 followed on August 5, 2025 as an incremental refinement, and the Opus line has since been Anthropic's flagship tier through Opus 4.5 and beyond.

## Questions and answers

### When was Claude Opus 4 released?

Claude Opus 4 was released by Anthropic on Thursday, May 22 2025.

### Who made Claude Opus 4?

Claude Opus 4 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 get?

Claude Opus 4 reports 3 tracked benchmark scores — BullshitBench v2: 34%; SWE-Bench Verified: 72.5%; GPQA Diamond: 79.6%. Tracked scores may come from lab reports or independent benchmarks; source details accompany the benchmark data.

### Is Claude Opus 4 open source?

No. Claude Opus 4 is a closed 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?

Anthropic's previous tracked release was Claude Sonnet 4 on May 22 2025. It was followed by Claude Opus 4.1 on Aug 5 2025.


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Canonical page: https://aireleasetracker.com/model/anthropic/claude-opus-4
Site index: https://aireleasetracker.com/llms.txt
Source: AI Release Tracker (https://aireleasetracker.com). Most benchmark scores come from lab launch material; gathered results identify the leaderboard that published them.