Kimi K2 0905 vs Mistral Small 4
Kimi K2 0905 leads Mistral Small 4 on the Artificial Analysis Intelligence Index, 15.3 to 11.3, and Mistral Small 4 costs 4.2x less per output token ($0.60 vs $2.50 per million). Updated October 22, 2026; 9 benchmarks have a result for both.
Kimi K2 0905 or Mistral Small 4: which to pick
Neither model has a coding score yet, so the two cannot be ranked on coding.
Pick Kimi K2 0905 for work measured by ALE-Bench or GPQA Diamond (Artificial Analysis run), where it leads.
- Shared results
- 9
- Kimi K2 0905 only
- 8
- Mistral Small 4 only
- 6
- Like-for-like categories
- 5 of 9
Only benchmarks that tested both models count toward a pick; a result only one model has is shown but not compared.
Which one for your work
Each card is decided by one number both models carry. Where only one has it, the card says so and makes no call.
Coding
Vibe Coding Index, six public coding benchmarks
No call
Neither has a coding score yet.
One side not measured
Intelligence
AA Intelligence Index
Kimi K2 0905
Kimi K2 0905 leads, 15.3 against 11.3.
Same board, both measured
Agentic work
AA Agentic Index
No call
Only Mistral Small 4 has a AA Agentic Index result, 0.8.
Directional only
Web design
Design Arena: websites
No call
Only Kimi K2 0905 has a Design Arena: websites result, 1088.
Directional only
Long documents
Listed context window
No call
Both take 262K tokens.
Listed by OpenRouter
Everyday cost
1K input + 500 output tokens
Mistral Small 4
Kimi K2 0905 $0.0019, Mistral Small 4 $0.0004 per turn.
List prices
At a glance
- Coding index
- Kimi K2 0905 not benchmarked, Mistral Small 4 not benchmarked.
- Widest category
- Agentic work, 32.2 points apart on average over 1 shared benchmark.
- Widest single gap
- τ²-Bench Telecom: Kimi K2 0905 73.4% against Mistral Small 4 41.2%, 32.2 points apart on a 0 to 100 scale.
- Output price
- Kimi K2 0905 $2.50 against Mistral Small 4 $0.60 per million output tokens, 4.2x apart.
- Context window
- Both take 262K tokens.
Benchmark by benchmark
First the score: boards each model leads, per category, where both have a result. Then every board, a category to a fold; bars are each result on a 0 to 100 scale, so compare the two in a row, not one row with another.
| Category | Kimi K2 0905 | Bars | Mistral Small 4 | Ties |
|---|---|---|---|---|
| Coding | 1 | 1 | ||
| Intelligence | 1 | 0 | ||
| Agentic work | 1 | 0 | ||
| Reasoning | 1 | 2 | ||
| General | 1 | 1 | ||
| All shared boards | 5 | 4 |
CodingLike-for-likeSix of these boards feed the Vibe Coding Index11
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Coding Index | Not measured | 26.6 | Only Mistral Small 4 measured |
| Vibe Code Bench (Vals AI) | Not measured | 0.0% | Only Mistral Small 4 measured |
| LiveCodeBench (Artificial Analysis run) | 61.0% | Not measured | Only Kimi K2 0905 measured |
| SciCode | Not measured | 38.8% | Only Mistral Small 4 measured |
| Terminal-Bench Hard (Artificial Analysis run) | 23.5% | 17.4% | Kimi K2 0905 |
| WeirdML | 36.7% | Not measured | Only Kimi K2 0905 measured |
| ALE-Bench | 267.1 | 497.6 | Mistral Small 4 |
| Neither model has a result on the other 32 boards here | |||
IntelligenceLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Intelligence Index | 15.3 | 11.3 | Kimi K2 0905 |
| Neither model has a result on the other 1 board here | |||
Agentic workLike-for-likePublic boards, shown as published, kept out of the index10
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Agentic Index | Not measured | 0.8 | Only Mistral Small 4 measured |
| τ²-Bench Telecom | 73.4% | 41.2% | Kimi K2 0905 |
| Neither model has a result on the other 39 boards here | |||
ReasoningLike-for-likePublic boards, shown as published, kept out of the index12
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| GPQA Diamond (Artificial Analysis run) | 76.7% | 76.9% | Mistral Small 4 |
| Humanity's Last Exam (Artificial Analysis run) | 6.4% | 9.9% | Mistral Small 4 |
| Kagi LLM Benchmark | 52.2% | 40.5% | Kimi K2 0905 |
| Neither model has a result on the other 19 boards here | |||
MathDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| AA Math Index | 57.3 | Not measured | Only Kimi K2 0905 measured |
| AIME 2025 (Artificial Analysis run) | 57.3% | Not measured | Only Kimi K2 0905 measured |
| Neither model has a result on the other 11 boards here | |||
KnowledgeDirectional onlyPublic boards, shown as published, kept out of the index1 board, none shared
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| MMLU Pro (Artificial Analysis run) | 81.9% | Not measured | Only Kimi K2 0905 measured |
| Neither model has a result on the other 17 boards here | |||
Web designDirectional onlyPublic boards, shown as published, kept out of the index2 boards, none shared
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| Design Arena: websites | 1088 | Not measured | Only Kimi K2 0905 measured |
| Design Arena: all code categories | 1098 | Not measured | Only Kimi K2 0905 measured |
| Neither model has a result on the other 7 boards here | |||
GeneralLike-for-likePublic boards, shown as published, kept out of the index11
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| IFBench | 41.7% | 48.2% | Mistral Small 4 |
| Long context reasoning (AA-LCR) | 53.0% | 49.7% | Kimi K2 0905 |
| DTBench | Not measured | 70.9% | Only Mistral Small 4 measured |
| LMCA | Not measured | 20.6% | Only Mistral Small 4 measured |
| Fiction.LiveBench | 66.7% | Not measured | Only Kimi K2 0905 measured |
| Neither model has a result on the other 41 boards here | |||
Image generationNot comparablePublic boards, shown as published, kept out of the index0 boards, none shared
| Benchmark | Kimi K2 0905 | Mistral Small 4 | Leader |
|---|---|---|---|
| Neither model has a result on 5 boards here | |||
What each workload costs
Three fixed token mixes at each model's listed price, so per-token rates become a bill.
Chat turn
1K input + 500 output tokens
Mistral Small 4 costs less
Repository review
50K input + 3K output tokens
Mistral Small 4 costs less
Agent loop
200K input + 10K output tokens
Mistral Small 4 costs less
Listed OpenRouter rates, without cache or batch discounts. A workload that does not fit a model's context window would need splitting.
Specification differences
The leading value in a row is marked; a row with a missing value names no leader. Our two rows are marked in red.
| Specification | MoonshotAI Kimi K2 0905 | Mistral Small 4 |
|---|---|---|
| Maker | Moonshot AI | Mistral AI |
| Weights | Open weights | Open weights |
| Released | September 4, 2025 | March 16, 2026 |
| Context window | 262K | 262K |
| Input $/Mtok | $0.60 | $0.15 |
| Output $/Mtok | $2.50 | $0.60 |
| Coding index | Not benchmarked | Not benchmarked |
| Independent measurements behind it | 0 | 1 |
| Cost per solved task | Not computable | Not computable |
| Source | OpenRouter listing | OpenRouter listing |
Questions
Is Kimi K2 0905 better than Mistral Small 4 for coding?
Neither model has a coding score yet, so the two cannot be ranked on coding. Pick Kimi K2 0905 for work measured by ALE-Bench or GPQA Diamond (Artificial Analysis run), where it leads.
Which is cheaper, Kimi K2 0905 or Mistral Small 4?
Kimi K2 0905 costs $0.60 per million input tokens and $2.50 per million output tokens; Mistral Small 4 costs $0.15 and $0.60. Cost per solved task is known for neither of them.
Which has the bigger context window, Kimi K2 0905 or Mistral Small 4?
Neither: both take 262K tokens.
How many benchmarks is the Kimi K2 0905 vs Mistral Small 4 comparison based on?
9 benchmarks have a result for both models as of October 22, 2026. Kimi K2 0905's coding index rests on 0 independent benchmarks and Mistral Small 4's on 1. Where only one model has a result, the page says so instead of naming a winner.