Claude Sonnet 5.5 vs MiniMax M3.1 Flash
Harvey LAB-AA 1.1?
Sonnet 5.5at max2.8
MiniMax M3.1 Flash—
| Benchmark | Sonnet 5.5 | MiniMax M3.1 Flash |
|---|---|---|
| Arena Text · creative writing | 1,465 · xhigh | — |
| Harvey LAB-AA 1.1 | 2.8 · max | — |
Specs
| Spec | Sonnet 5.5 | MiniMax M3.1 Flash |
|---|---|---|
| Input, per 1M | $2 | $0.15 |
| Output, per 1M | $10 | $0.60 |
| Cost per task? | $0.88 | $0.22 |
| Speed, tok/s | 106 | 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
Sonnet 5.5 → MiniMax M3.1 Flash
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.
MiniMax M3.1 Flash → Sonnet 5.5
No forced tool use›
Forced tool_choice any or tool returns HTTP 400; remove the forced choice.
Replace disabled thinking›
Disabled thinking returns HTTP 400; use between_tools for the lowest thinking setting.
No manual thinking budgets›
Manual thinking budgets and extra between_tools fields return HTTP 400; remove manual budgets and send between_tools without display, budget_tokens or block_binding.
Remove sampling parameters›
Non-default temperature, top_p or top_k returns HTTP 400; remove these parameters.
No assistant prefill›
A prefilled final assistant turn returns HTTP 400; remove that prefill.
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.