Model Comparison
Kimi K3 vs Mistral Medium 3.5Which is better in 2026?
Kimi K3 significantly outperforms across most benchmarks. Mistral Medium 3.5 is 2.0x cheaper per token.
Verdict: Kimi K3 vs Mistral Medium 3.5 — which is better?
Kimi K3 (by Moonshot AI) and Mistral Medium 3.5 (by Mistral AI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.
Kimi K3 outperforms in 2 benchmarks (BrowseComp, GDPval-AA), while Mistral Medium 3.5 is better at 0 benchmarks. Kimi K3 significantly outperforms across most benchmarks.
On price, Mistral Medium 3.5 is roughly 2.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Kimi K3 also accepts a larger context window (1,048,576 input tokens), making it the stronger choice for long documents and large codebases.
Choose Kimi K3 if…
- you want the strongest raw capability — it leads on 2 of 2 shared benchmarks
- you process long inputs — it offers a 1,048,576 token context window
- you want the most recent training data — it shipped Jul 2026
Choose Mistral Medium 3.5 if…
- cost matters — it's about 2.0x cheaper per token
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
Kimi K3 outperforms in 2 benchmarks (BrowseComp, GDPval-AA), while Mistral Medium 3.5 is better at 0 benchmarks.
Kimi K3 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Kimi K3 ($3.00/1M tokens) is 2.0x more expensive than Mistral Medium 3.5 ($1.50/1M tokens).
For output processing, Kimi K3 ($15.00/1M tokens) is 2.0x more expensive than Mistral Medium 3.5 ($7.50/1M tokens).
In conclusion, Kimi K3 is more expensive than Mistral Medium 3.5.*
* Using a 3:1 ratio of input to output tokens
Model Size
Parameter count comparison
Kimi K3 has 2672.0B more parameters than Mistral Medium 3.5, making it 2087.5% larger.
Context Window
Maximum input and output token capacity
Kimi K3 accepts 1,048,576 input tokens compared to Mistral Medium 3.5's 256,000 tokens. Kimi K3 can generate longer responses up to 1,048,576 tokens, while Mistral Medium 3.5 is limited to 256,000 tokens.
Input Capabilities
Supported data types and modalities
Both Kimi K3 and Mistral Medium 3.5 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Kimi K3
Mistral Medium 3.5
Release Timeline
When each model was launched
Kimi K3 was released on 2026-07-16, while Mistral Medium 3.5 was released on 2026-04-29.
Kimi K3 is 3 months newer than Mistral Medium 3.5.
Jul 16, 2026
1 weeks ago
2mo newerApr 29, 2026
2 months ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
Kimi K3 is available from Moonshot AI. Mistral Medium 3.5 is available from Mistral AI.
Kimi K3
Mistral Medium 3.5
Outputs Comparison
Key Takeaways
Kimi K3
View detailsMoonshot AI
Mistral Medium 3.5
View detailsMistral AI
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against Kimi K3 and Mistral Medium 3.5 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about Kimi K3 vs Mistral Medium 3.5.