Model vs model
Kimi K3.1 Pro vs Mistral Medium 3.5
At a glance
Longer bar means the bigger number.
Open or closed · can you download the model and run it yourself?
Blended price · per 1M tokens, lower is better
Intelligence Index · Artificial Analysis, higher is better
Context window · tokens it can read at once
Where they sit among all 45 models
Kimi K3.1 Pro ranks 3rd of the 40 models with an Intelligence Index, Mistral Medium 3.5 33rd. Up and to the left is smarter for less money. Hover or tap a dot for its numbers, then click it to compare that model with Kimi K3.1 Pro.
Which one to pick
Pick Kimi K3.1 Pro if
- you want the higher overall score (55.1 vs 14.2)
- you care about Terminal-Bench 4.0 (terminal tasks): 67.2 vs 0
- you care about Humanity's Last Exam (hard reasoning): 52.5 vs 13.8
- you need a longer context window (1.05M vs 262K tokens)
Pick Mistral Medium 3.5 if
- you want the lower bill ($3 vs $4 per 1M tokens blended)
- you need to send PDFs
Kimi K3.1 Pro’s “controversial” take on humans
We asked Kimi K3.1 Pro and 13 other models the same question three times each: “What is your most controversial take about humans? Give your own honest view, not a survey of opinions, and don't hedge.” Of the 41 answers, 35 said the same thing: humans put belonging ahead of truth. Kimi K3.1 Pro gave it all three times. Mistral Medium 3.5 wasn’t in that test. Read the full story.
Kimi K3.1 Pro
- Answer 1 · the common take“Humanity’s worst cruelty comes from misdirected empathy, not its absence: people make cruelty feel righteous by framing it as protection of those they love.”
- Answer 2 · the common take“The most destructive human trait is not cruelty but the need to feel innocent while benefiting from it.”
- Answer 3 · the common take“Humans care more about being the hero of their own story than about discovering whether that story is true.”
Answers exactly as the models wrote them. “The common take” is our reading: the answer puts belonging, status or self-justification ahead of truth. How we ran it
How smart is each one?
Of the 10 scores both models have, Kimi K3.1 Pro is ahead on every one.
Every intelligence score we have
Out of 100, higher is better. Kimi K3.1 Pro Mistral Medium 3.5
Overall
Intelligence Index
55.114.2
By area
Coding
46.9Kimi K3.1 Pro: not scored yet
Agentic work
7Kimi K3.1 Pro: not scored yet
By field of work
Finance & accounting
56.514Legal
55.816.1Healthcare & medicine
14.8Kimi K3.1 Pro: not scored yet
Economics
6020.4Engineering
55.917.3Strategy & operations
59.411.9
Benchmarks
Hard reasoning · Humanity's Last Exam
52.513.8Science · GPQA Diamond
74.8Kimi K3.1 Pro: not scored yet
Scientific coding · SciCode
60.840.2Terminal tasks · Terminal-Bench 4.0
67.20Tool use · τ-Bench Banking
15.1Kimi K3.1 Pro: not scored yet
Instruction following · IFBench
68.8Kimi K3.1 Pro: not scored yet
Long documents · AA-LCR
86.369.3Uncensored · UGI
49.9Kimi K3.1 Pro: not scored yet
The specs
| Spec | Kimi K3.1 Pro | Mistral Medium 3.5 |
|---|---|---|
| Input price | $2 per 1M | $1.50 per 1M |
| Output price | $10 per 1M | $7.50 per 1M |
| Cost per test task | $2.11 | $0.5020 |
| Context window | 1.05M | 262K |
| Max output | 1.05M | 262K |
| Accepts | Text, Image, Video | Text, Image, PDF |
| Open weights | Yes | Yes |
| Lab | Kimi | Mistral AI |
| Released | Oct 2026 | Apr 2026 |
| Knowledge cutoff | Not published | Not published |
Blended price weighs 3 parts input to 1 part output. List prices from models.dev. Cost per test task from Artificial Analysis.
Questions
Is Kimi K3.1 Pro or Mistral Medium 3.5 cheaper?
Mistral Medium 3.5 is cheaper. It charges $1.50 per 1M input tokens and $7.50 per 1M output tokens, against $2 and $10 for Kimi K3.1 Pro. Blended 3 parts input to 1 part output, that is $3 against $4 per 1M tokens.
Are Kimi K3.1 Pro and Mistral Medium 3.5 open source?
Both are open-weights models: Kimi and Mistral AI publish the weights, so you can download them and run them on your own hardware, or call them through any host's API. Check each model's license before you ship it.
Which is smarter, Kimi K3.1 Pro or Mistral Medium 3.5?
Kimi K3.1 Pro scores higher on the Artificial Analysis Intelligence Index, 55.1 against 14.2 for Mistral Medium 3.5. The biggest differences are on Terminal-Bench 4.0 (67.2 vs 0) and Humanity's Last Exam (52.5 vs 13.8).
Which has the longer context window?
Kimi K3.1 Pro accepts 1.05M tokens, against 262K for Mistral Medium 3.5.
Can I compare Kimi K3.1 Pro and Mistral Medium 3.5 on my own prompt?
Yes. ModelCompare sends one prompt to both models at once and shows each answer side by side with what it cost. You can try it free without an account.
Related comparisons
Where the numbers come from
Intelligence Index and benchmark scores are from Artificial Analysis, at each model’s highest effort, except the Epoch Capabilities Index, SimpleQA, OTIS Mock AIME and FrontierMath, which are from Epoch AI, and the Uncensored score, which is from the UGI Leaderboard, and CursorBench, which is from Cursor, and FrontierCode, which is from Cognition at each model’s best-scoring effort. The hallucination test is ours: questions with one exact answer, fake evidence pushed against right answers and requests that tempt a model to name packages that don’t exist. Prices are list prices from models.dev. Example answers come from our own test runs. Updated November 13, 2026.