GPT-5.1 Chat vs Kimi K2 Thinking Turbo vs Magistral Medium
GPT-5.1 Chat comes out ahead, 52 to 36 and 31 on our weighted score, though Magistral Medium is 20% cheaper per token.
- Our pick
OpenAIGPT-5.1 Chat
52/100- ECI—
- Price$1.25 / $10.00
- Context128K
Moonshot AIKimi K2 Thinking Turbo
36/100- ECI—
- Price—
- Context262K
Mistral AIMagistral Medium
31/100- ECI—
- Price$2.00 / $5.00
- Context128K
GPT-5.1 Chat is our pick
GPT-5.1 Chat is the better all-round choice, scoring 52/100 against Kimi K2 Thinking Turbo (36) and Magistral Medium (31). It leads on inputs & features. Kimi K2 Thinking Turbo wins on context window. The score weighs inputs & features 60%, context window 40%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceMagistral MediumMagistral Medium $2.75 · GPT-5.1 Chat $3.44 per 1M tokens (3:1 blend) · Kimi K2 Thinking Turbo unpriced
- Longest contextKimi K2 Thinking TurboKimi K2 Thinking Turbo 262,144 · GPT-5.1 Chat 128,000 · Magistral Medium 128,000 tokens
- Widest inputsGPT-5.1 ChatGPT-5.1 Chat: Text, Images · Kimi K2 Thinking Turbo: Text · Magistral Medium: Text
- Self-hostingKimi K2 Thinking TurboPublishes downloadable weights
| Measure | Weight | GPT-5.1 Chat | Kimi K2 Thinking Turbo | Magistral Medium |
|---|---|---|---|---|
| Inputs & features | 60% | 70 | 35 | 35 |
| Context window | 40% | 24 | 37 | 24 |
| Overall | 100% | 52/100 | 36/100 | 31/100 |
Left out because at least one model lacks the data: capability and price. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | GPT-5.1 ChatOpenAI | Kimi K2 Thinking TurboMoonshot AI | Magistral MediumMistral AI |
|---|---|---|---|
| Capability | |||
| Capabilities Index (ECI) | — | — | — |
| ECI rank | — | — | — |
| Price per million tokens | |||
| Input | $1.25 (best) | — | $2.00 |
| Output | $10.00 | — | $5.00 (best) |
| Cached input | — | — | — |
| Blended (3:1) | $3.44 | — | $2.75 (best) |
| Long-context rate | Same rate | — | Same rate |
| Price source | Median of 2 providers | — | Official Mistral API |
| Limits | |||
| Context window | 128,000 tokens | 262,144 tokens (best) | 128,000 tokens |
| Max output | 16,384 tokens | 262,144 tokens (best) | 16,384 tokens |
| Inputs and features | |||
| Text | Yes | Yes | Yes |
| Images | Yes | No | No |
| PDFs | No | No | No |
| Audio | No | No | No |
| Video | No | No | No |
| Reasoning | Yes | Yes | Yes |
| Tool calling | Yes | Yes | Yes |
| Structured output | Yes | No | No |
| Availability | |||
| Weights | Proprietary | Open | Proprietary |
| API model ID | — | — | magistral-medium-latest |
| API providers | 2 | — | 4 (best) |
| Released | Nov 13, 2025 | Nov 6, 2025 | Mar 17, 2025 |
| Knowledge cutoff | Sep 30, 2024 | Aug 2024 | Jun 2025 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- GPT-5.1 Chat$32.50
- Kimi K2 Thinking Turbo—
- Magistral Medium$30.00
Which should you choose?
Which is better: GPT-5.1 Chat, Kimi K2 Thinking Turbo or Magistral Medium?
GPT-5.1 Chat is the better all-round choice, scoring 52/100 against Kimi K2 Thinking Turbo (36) and Magistral Medium (31). It leads on inputs & features. Kimi K2 Thinking Turbo wins on context window. The score weighs inputs & features 60%, context window 40%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, GPT-5.1 Chat, Kimi K2 Thinking Turbo or Magistral Medium?
Magistral Medium is cheaper at $2.00 input / $5.00 output per million tokens (official Mistral API price). GPT-5.1 Chat costs $1.25 input / $10.00 output per million tokens (median across 2 API providers). At a typical mix of three input tokens to one output token, that is $2.75 per million tokens for Magistral Medium versus $3.44 for GPT-5.1 Chat (1.3× as much). Kimi K2 Thinking Turbo has no published per-token price.
Which scores higher on benchmarks?
There is no independent benchmark that covers all three models yet. GPT-5.1 Chat has not been scored yet, Kimi K2 Thinking Turbo has not been scored yet and Magistral Medium has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for GPT-5.1 Chat, Kimi K2 Thinking Turbo and Magistral Medium yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. All three support tool calling for agent workflows.
Which has the bigger context window?
Kimi K2 Thinking Turbo has the largest context window at 262,144 tokens, against 128,000 for GPT-5.1 Chat and 128,000 for Magistral Medium. Maximum output per response: GPT-5.1 Chat up to 16,384, Kimi K2 Thinking Turbo up to 262,144, Magistral Medium up to 16,384 tokens.
Which can read images, PDFs, audio or video?
GPT-5.1 Chat accepts text and images; Kimi K2 Thinking Turbo accepts text; Magistral Medium accepts text. GPT-5.1 Chat handles the widest range of inputs.
Are any of these open source?
Kimi K2 Thinking Turbo publishes its weights and can be self-hosted; GPT-5.1 Chat and Magistral Medium is proprietary.
Which is newer?
GPT-5.1 Chat is the newest, released Nov 13, 2025. Kimi K2 Thinking Turbo came out Nov 6, 2025; Magistral Medium came out Mar 17, 2025. Knowledge cutoff: GPT-5.1 Chat Sep 30, 2024, Kimi K2 Thinking Turbo Aug 2024, Magistral Medium Jun 2025.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
