Claude Opus 5.5 vs MiniMax M3.1 Flash
| Benchmark | Opus 5.5 | MiniMax M3.1 Flash |
|---|---|---|
| Arena Text · creative writing | 1,519 · high | — |
| EQ-Bench Longform Creative Writing 1.11 | 84.6 | — |
| EQ-Bench Creative Writing v3 | 2,050.8 | — |
| Lech Mazur Short-Story | 3.7 · high | — |
| Harvey LAB-AA 1.1 | 4.2 · max | — |
Specs
| Spec | Opus 5.5 | MiniMax M3.1 Flash |
|---|---|---|
| Input, per 1M | $4 | $0.15 |
| Output, per 1M | $20 | $0.60 |
| Cost per task? | $1.34 | $0.22 |
| Speed, tok/s | 82 | 121 |
| Context | 1M | 1M |
| Weights | Closed | Closed |
| Released | Sep 2026 | Oct 2026 |
| See images | ✓ | ✓ |
| Read PDFs | ✓ | — |
| Hear audio | — | — |
| Watch video | — | ✓ |
| Call tools | ✓ | ✓ |
| Force a tool call | — | ? |
| Return strict JSON | ✓ | — |
| Search the web | ✓ | ? |
| Run code | ✓ | ? |
| Use a computer | ✓ | ? |
What breaks when you switch
No PDF input
No strict JSON
Complete model response must be appended›
In multi-turn tools, preserve the complete assistant response, including reasoning_content and tool_calls, to maintain reasoning continuity.
No forced tool use›
Forced tool_choice any or tool returns HTTP 400; remove the forced choice.
Thinking is always on›
Disabled thinking or a manual budget returns HTTP 400; omit thinking or use adaptive thinking.
Remove sampling parameters›
Non-default temperature, top_p or top_k returns HTTP 400; omit these parameters and use prompting.
No assistant prefill›
Assistant prefill returns HTTP 400; use structured outputs or system instructions, with system instructions on Bedrock.
Old computer tool rejected · Claude API / Google Cloud›
The computer_20251124 tool returns HTTP 400 on the Claude API and Google Cloud; use computer_toolset_20260801 there.
Return thinking blocks unmodified›
Edited, reordered or partially dropped thinking blocks return HTTP 400; echo assistant messages complete and unmodified with tool results.