Claude Haiku 4.5 vs gpt-oss-20b
Anthropic Claude Haiku 4.5 | OpenAI gpt-oss-20b | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Oct 15 2025 | Aug 5 2025 |
| Access | Proprietary | Open Weight |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given 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. | 77% | — |
Coding SWE-Bench VerifiedReal 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. | 73.3% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 73% | — |
| Timeline | ||
| Release gap | gpt-oss-20b shipped 71 days before Claude Haiku 4.5 | |
Which is better: Claude Haiku 4.5 or gpt-oss-20b?
Claude Haiku 4.5 and gpt-oss-20b don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. gpt-oss-20b shipped 71 days before Claude Haiku 4.5, so benchmark comparisons should account for the intervening progress.
Claude Haiku 4.5 is proprietary, while gpt-oss-20b is open weight.
Direct benchmark comparisons are unavailable — Claude Haiku 4.5 and gpt-oss-20b don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude Haiku 4.5 was released by Anthropic on Oct 15 2025.
gpt-oss-20b was released by OpenAI on Aug 5 2025.
Claude Haiku 4.5 is a proprietary model released by Anthropic. gpt-oss-20b is an open weight model released by OpenAI.
Other comparisons
Claude Haiku 4.5 vs Gemini Omnigpt-oss-20b vs Gemini OmniClaude Haiku 4.5 vs Muse Spark 1.1gpt-oss-20b vs Muse Spark 1.1Claude Haiku 4.5 vs Grok 4.5gpt-oss-20b vs Grok 4.5Claude Haiku 4.5 vs DeepSeek-V4-Progpt-oss-20b vs DeepSeek-V4-ProClaude Haiku 4.5 vs Mistral Medium 3.5gpt-oss-20b vs Mistral Medium 3.5Claude Haiku 4.5 vs Kimi K2.7 Codegpt-oss-20b vs Kimi K2.7 Code