In short
How they differ.
Worked out from the figures below. Prices and specs are the makers' own, read Oct 20, 2026.
- Mistral Medium 3.5 is cheaper per output token: $7.50 against $10 per million tokens, so GPT-6.1 Sol costs 1.3 times as much.
- GPT-6.1 Sol reads more at once: a context window of 1M tokens against 256K.
- Mistral Medium 3.5 can be downloaded and run on your own machine; GPT-6.1 Sol can't.
- No independent board we follow ranks both models yet.
Side by side
The specs.
| GPT-6.1 Sol | Mistral Medium 3.5 | |
|---|---|---|
| Made by | OpenAI · US | Mistral AI · France |
| Released | Sep 29, 2026 | Apr 28, 2026 |
| Price per 1M tokens | $2 in / $10 out | $1.50 in / $7.50 out |
| Context window | 1M | 256K |
| Takes in | text, image | text, image |
| Download and run it yourself | No | Yes (Modified MIT) |
| Size | Not published | 128B (dense) parameters |
| Maker says | “Near-Astra performance for complex work at a lower cost.” | “Our frontier-class multimodal model optimized for agentic and coding use cases.” |
| Sources | Prices, Oct 20, 2026 · Description | Prices, Oct 20, 2026 · Description |
Independent tests
Where they place.
Position on each board we follow (1 is best). Epoch AI's and Vectara's scores are shown; the other boards are linked for their own figures.
| Board | GPT-6.1 Sol | Mistral Medium 3.5 |
|---|---|---|
| Epoch Capabilities IndexEpoch AI, Oct 20, 2026 | #3166.32 | Not listed |
| LMArena coding chatsLMArena, Oct 15, 2026 | #10 | Not listed |
| LMArena WebDevLMArena, Oct 19, 2026 | #4 | Not listed |
| LMArena visionLMArena, Oct 19, 2026 | #9 | Not listed |
| LMArena Agent ArenaLMArena, Oct 19, 2026 | #4 | Not listed |
| SWE-Bench ProScale AI, Sep 22, 2026 | #7 | Not listed |
| MultiChallengeScale AI, Feb 3, 2026 | #1 | Not listed |
| Vals IndexVals AI, Oct 19, 2026 | #7 | Not listed |
| Terminal-Bench 4.0Vals AI, Oct 19, 2026 | #7 | Not listed |
| Vibe Code BenchVals AI, Oct 18, 2026 | #8 | Not listed |
| ProofBenchVals AI, Oct 12, 2026 | #5 | Not listed |
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