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Model comparison

Kimi K2.6 vs Mistral Medium 3.5 128B

Data verified

Head-to-head evidence from 18 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

Moonshot AI
58.73/100
No comparison
0 category wins1 category wins

Public leaderboard positions: Kimi K2.6 #61 (Estimated); Mistral Medium 3.5 128B unranked (Not scored). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Kimi K2.6 and Mistral Medium 3.5 128B share 18 comparable benchmark results. 1 of 8 categories are comparable. 32 results are unique to Kimi K2.6; 7 to Mistral Medium 3.5 128B.

Updated July 27, 2026
Shared results
18
Kimi K2.6 only
32
Mistral Medium 3.5 128B only
7
Comparable categories
1 / 8

Treat this as a split decision. Kimi K2.6 makes more sense if you want the cheaper token bill; Mistral Medium 3.5 128B is the better fit if coding is the priority.

Confidence note. This is a partial-evidence comparison with 18 shared benchmark results across 6 evidence categories; 1 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Kimi K2.6 and Mistral Medium 3.5 128B finish on the same BenchAlign overall score, so this is less about a single winner and more about where the edge shows up. The BenchAlign headline says tie; the benchmark table is where the real choice happens.

Mistral Medium 3.5 128B is also the more expensive model on tokens at $1.50 input / $7.50 output per 1M tokens, versus $0.95 input / $4.00 output per 1M tokens for Kimi K2.6.

Category breakdown

Exact category averages are shown below. Not measured means BenchLM does not have enough sourced public coverage for that model and category.

Category scores and score margins for Kimi K2.6 and Mistral Medium 3.5 128B
CategoryKimi K2.6ΔMistral Medium 3.5 128B
CodingKimi K2.664.4Margin 13.2Mistral Medium 3.5 128B77.6
AgenticKimi K2.673.5MarginNo overlapMistral Medium 3.5 128BNot measured
KnowledgeKimi K2.642.2MarginNo overlapMistral Medium 3.5 128BNot measured
MathKimi K2.667.1MarginNo overlapMistral Medium 3.5 128BNot measured
MultimodalKimi K2.679.8MarginNo overlapMistral Medium 3.5 128BNot measured

Decisive benchmark drivers

The largest measured benchmark gaps in this matchup, with exact reported values.

More
A · Kimi K2.6B · Mistral Medium 3.5 128B
  1. SWE-bench Verified

    Coding
    Source ↗
    A 80.2%B 77.6%
    Winner: Kimi K2.6Δ 2.6
    SWE-bench Verified: Kimi K2.6 scored 80.2%; Mistral Medium 3.5 128B scored 77.6%. Kimi K2.6 wins this benchmark.

Operational comparison

Runtime and commercial metrics are compared only when both models have a complete sourced value.

MetricKimi K2.6Mistral Medium 3.5 128BComparison
Input / output priceUSD per 1M tokensKimi K2.6$0.95 input / $4 outputMistral Medium 3.5 128B$1.5 input / $7.5 outputKimi K2.6 has the lower combined listed price.
Generation speedtokens per secondKimi K2.6Not availableMistral Medium 3.5 128BNot availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenKimi K2.6Not availableMistral Medium 3.5 128BNot availableA complete latency comparison is not available.
Context windowmaximum listed tokensKimi K2.6256KMistral Medium 3.5 128B256KListed context windows are equal.

Benchmark Deep Dive

Agentic
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
Terminal-Bench 2.0Source 66.7%Not comparable
BrowseCompSource 83.2%Not comparable
OSWorld-VerifiedSource 73.1%Not comparable
ToolathlonSource 50%Not comparable
MCP AtlasSource 55.9%Not comparable
Claw-EvalSource 62.3%Not comparable
DeepSearchQASource 92.5%Not comparable
WideResearchSource 80.8%Not comparable
AA Agentic IndexSource 30.3%19.0%Kimi K2.6 leads
τ²-bench resultsSource 95.9%94.2%Kimi K2.6 leads
GDPval-AASource 34.4%21.6%Kimi K2.6 leads
GDPval-AASource 1188933Kimi K2.6 leads
APEX-Agents-AASource 28.5%Not comparable
Gert LabsSource 56.82%39.10%Kimi K2.6 leads
ResearchClawBenchSource 18.0%Not comparable
OSWorld 2.0Source 4.6%Not comparable
τ³-bench resultsSource 91.4%Not comparable
AA EnterpriseOps-GymSource 33.7%Not comparable
AA Harvey LABSource 69.1%Not comparable
terminalBenchHardSource 33.3%Not comparable
AA BriefcaseSource 516Not comparable
AA Tau3 BankingSource 14.4%Not comparable
CodingMistral Medium 3.5 128B wins
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
SWE-bench VerifiedSource 80.2%77.6%Kimi K2.6 leads
LiveCodeBench v6Source 89.6%Not comparable
SWE-bench ProSource 58.6%Not comparable
SWE MultilingualSource 76.7%Not comparable
SciCodeSource 52.2%Not comparable
Terminal-Bench 2.0Source 66.7%Not comparable
Vibe Code BenchSource 37.89%Not comparable
cursorBench31Source 47.6%Not comparable
AA Coding IndexSource 61.8%46.9%Kimi K2.6 leads
AA-SciCodeSource 53.5%39.6%Kimi K2.6 leads
Reasoning
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
AA-LCRSource 69.7%61.0%Kimi K2.6 leads
CritPtSource 8.0%0.0%Kimi K2.6 leads
Knowledge
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
GPQASource 90.5%Not comparable
GPQA-DSource 90.5%Not comparable
HLESource 34.7%Not comparable
Artificial Analysis Intelligence IndexSource 44.2%29.9%Kimi K2.6 leads
AA-GPQA DiamondSource 91.1%74.8%Kimi K2.6 leads
AA-HLESource 35.9%12.8%Kimi K2.6 leads
AA-Omniscience IndexSource 6.4%-36.3%Kimi K2.6 leads
AA-Omniscience AccuracySource 32.8%25.1%Kimi K2.6 leads
AA-Omniscience Hallucination RateSource 39.3%82.0%Kimi K2.6 leads
AA Openness IndexSource 33.3%Not comparable
Math
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
AIME26Source 96.4%Not comparable
HMMT Feb 2026Source 92.7%Not comparable
MMAnswerBenchSource 86.0%Not comparable
FrontierMath v2 (Tiers 1-3)Source 38.966%Not comparable
FrontierMath v2 (Tier 4)Source 14.580%Not comparable
Multimodal
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
MMMU-ProSource 79.4%Not comparable
MMMU-Pro w/ PythonSource 80.1%Not comparable
CharXivSource 80.4%Not comparable
MathVisionSource 87.4%Not comparable
V*Source 96.9%Not comparable
AA-MMMU-ProSource 79.4%64.9%Kimi K2.6 leads
Design Arena WebsiteSource 1302Not comparable
Inst. Following
BenchmarkKimi K2.6Mistral Medium 3.5 128BResult
AA-IFBenchSource 76.0%68.8%Kimi K2.6 leads
Frequently Asked Questions (2)

Which is better, Kimi K2.6 or Mistral Medium 3.5 128B?

Kimi K2.6 and Mistral Medium 3.5 128B are tied on the BenchAlign overall score, so the right pick depends on which category matters most for your use case.

Which is better for coding, Kimi K2.6 or Mistral Medium 3.5 128B?

Mistral Medium 3.5 128B has the edge for coding in this comparison, averaging 77.6 versus 64.4. Inside this category, AA Coding Index is the benchmark that creates the most daylight between them.

Self-host vs API cost

Estimates at 50,000 req/day · 1000 tokens/req average.

Kimi K2.6
API / mo$3,713
Self-host / mo$18,221
Break-even326M/day
Mistral Medium 3.5 128B
API / mo$6,750
Self-host / moNot listed
Break-even
Proprietary model — self-hosting not applicable.
Model the full break-even

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Last updated: July 27, 2026

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