Mistral Small 3.2 vs GPT-6 Luna
GPT-6 Luna comes out ahead, 86 to 52 on our weighted score, though Mistral Small 3.2 is 25% cheaper per token.
Mistral AI
Mistral Small 3.2
52/100- ECI131.7
- Price$0.10 / $0.30
- Context128K
- Our pick
OpenAI
GPT-6 Luna
86/100- ECI—
- Price$0.10 / $0.50
- Context1.05M
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GPT-6 Luna is our pick
GPT-6 Luna is the better all-round choice, scoring 86/100 against Mistral Small 3.2 (52). It leads on capability, inputs & features and context window. Mistral Small 3.2 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%. Capability uses the average of shared benchmarks (GPQA Diamond and OTIS Mock AIME 2024–2025), because GPT-6 Luna has no Capabilities Index score yet.
- CapabilityGPT-6 LunaShared benchmarks: GPT-6 Luna 94.7% · Mistral Small 3.2 39.7%
- Lowest priceMistral Small 3.2Mistral Small 3.2 $0.15 · GPT-6 Luna $0.20 per 1M tokens (3:1 blend)
- Longest contextGPT-6 LunaGPT-6 Luna 1,050,000 · Mistral Small 3.2 128,000 tokens
- Widest inputsGPT-6 LunaMistral Small 3.2: Text, Images · GPT-6 Luna: Text, Images, PDFs
- Self-hostingMistral Small 3.2Publishes downloadable weights
| Measure | Weight | Mistral Small 3.2 | GPT-6 Luna |
|---|---|---|---|
| CapabilityShared benchmarks | 50% | 40 | 95 |
| Price | 25% | 89 | 83 |
| Inputs & features | 15% | 50 | 80 |
| Context window | 10% | 24 | 61 |
| Overall | 100% | 52/100 | 86/100 |
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | ||
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 131.7 | — |
| ECI rank | #123 of 148 | — |
| GPQA DiamondGraduate-level science questions | 49.1% | 90.5% (best) |
| FrontierMath Tiers 1–3Research-level mathematics | — | 79.0% |
| OTIS Mock AIME 2024–2025Competition mathematics | 30.3% | 98.9% (best) |
| SimpleQA VerifiedShort factual questions | — | 41.4% |
| Price per million tokens | ||
| Input | $0.10 | $0.10 |
| Output | $0.30 (best) | $0.50 |
| Cached input | — | $0.01 |
| Blended (3:1) | $0.15 (best) | $0.20 |
| Long-context rate | Same rate | Over 272K: $0.20 / $0.75 |
| Price source | Official Mistral API | Official OpenAI API |
| Limits | ||
| Context window | 128,000 tokens | 1,050,000 tokens (best) |
| Max output | 16,384 tokens | 128,000 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | Yes |
| Audio | No | No |
| Video | No | No |
| Reasoning | No | Yeslow · medium · high · xhigh · max |
| Tool calling | Yes | Yes |
| Structured output | No | Yes |
| Availability | ||
| Weights | Open | Proprietary |
| API model ID | mistral-small-2506 | gpt-6-luna |
| API providers | 6 | 24 (best) |
| Released | Jun 20, 2025 | Sep 22, 2026 |
| Knowledge cutoff | Mar 2025 | May 18, 2026 |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
Mistral Small 3.2$1.60
GPT-6 Luna$2.00
Which should you choose?
Which is better: Mistral Small 3.2 or GPT-6 Luna?
GPT-6 Luna is the better all-round choice, scoring 86/100 against Mistral Small 3.2 (52). It leads on capability, inputs & features and context window. Mistral Small 3.2 wins on price. The score weighs capability 50%, price 25%, inputs & features 15%, context window 10%. Capability uses the average of shared benchmarks (GPQA Diamond and OTIS Mock AIME 2024–2025), because GPT-6 Luna has no Capabilities Index score yet.
Which is cheaper, Mistral Small 3.2 or GPT-6 Luna?
Mistral Small 3.2 is cheaper at $0.10 input / $0.30 output per million tokens (official Mistral API price). GPT-6 Luna costs $0.10 input / $0.50 output per million tokens (official OpenAI API price). At a typical mix of three input tokens to one output token, that is $0.15 per million tokens for Mistral Small 3.2 versus $0.20 for GPT-6 Luna (1.3× as much).
Which scores higher on benchmarks?
Not every model here has a Capabilities Index score, so we compare the average of shared benchmarks (GPQA Diamond and OTIS Mock AIME 2024–2025): GPT-6 Luna 94.7% and Mistral Small 3.2 39.7%. On individual benchmarks: GPQA Diamond — GPT-6 Luna 90.5%, Mistral Small 3.2 49.1%; OTIS Mock AIME 2024–2025 — GPT-6 Luna 98.9%, Mistral Small 3.2 30.3%.
Which is better for coding?
There are no published SWE-bench Verified results for Mistral Small 3.2 and GPT-6 Luna yet, so there is no like-for-like coding score. On overall capability, GPT-6 Luna leads, which tends to carry over to coding, but test on your own codebase. Both support tool calling for agent workflows.
Which has the bigger context window?
GPT-6 Luna has the largest context window at 1,050,000 tokens, against 128,000 for Mistral Small 3.2. Maximum output per response: Mistral Small 3.2 up to 16,384, GPT-6 Luna up to 128,000 tokens.
Which can read images, PDFs, audio or video?
Mistral Small 3.2 accepts text and images; GPT-6 Luna accepts text, images and PDFs. GPT-6 Luna handles the widest range of inputs.
Are any of these open source?
Mistral Small 3.2 publishes its weights and can be self-hosted; GPT-6 Luna is proprietary.
Which is newer?
GPT-6 Luna is the newest, released Sep 22, 2026. Mistral Small 3.2 came out Jun 20, 2025. Knowledge cutoff: Mistral Small 3.2 Mar 2025, GPT-6 Luna May 18, 2026.
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.