gpt-oss-120b vs Claude Opus 5
| OpenAI gpt-oss-120b | Anthropic Claude Claude Opus 5 | |
|---|---|---|
| Vendor | OpenAI | Anthropic Claude |
| Context window | 131,072 | 1,000,000 |
| Max output | 131,072 | 128,000 |
| Reasoning | No | Yes |
| Tool calling | Yes | Yes |
| File input | No | Yes |
| Input | text | text, image, file |
| Output | text | text |
| Released | — | 2026-07-24 |