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Model comparison

Grok 4.20 vs Kimi K2.5

Data verified

Head-to-head evidence from 8 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

53.88/100
Margin
4.9pts
winning →
Kimi K2.5
Moonshot AI
58.78/100
1 category wins3 category wins

Public leaderboard positions: Grok 4.20 #93 (Estimated); Kimi K2.5 #60 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. Grok 4.20 and Kimi K2.5 share 8 comparable benchmark results. 4 of 8 categories are comparable. 11 results are unique to Grok 4.20; 55 to Kimi K2.5.

Updated July 28, 2026
Shared results
8
Grok 4.20 only
11
Kimi K2.5 only
55
Comparable categories
4 / 8

Pick Kimi K2.5 if you want the stronger benchmark profile. Grok 4.20 only becomes the better choice if coding is the priority or you need the larger 2M context window.

Confidence note. This is a partial-evidence comparison with 8 shared benchmark results across 4 evidence categories; 4 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

Kimi K2.5 is clearly ahead on the BenchAlign aggregate, 58.78 to 53.88. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Kimi K2.5's sharpest advantage is in multimodal & grounded, where it averages 78.5 against 70.1. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 47.1% to 50.8%. Grok 4.20 does hit back in coding, so the answer changes if that is the part of the workload you care about most.

Grok 4.20 is also the more expensive model on tokens at $2.00 input / $6.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5. That is roughly 2.0x on output cost alone. Grok 4.20 is the reasoning model in the pair, while Kimi K2.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. Grok 4.20 gives you the larger context window at 2M, compared with 256K for Kimi K2.5.

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 Grok 4.20 and Kimi K2.5
CategoryGrok 4.20ΔKimi K2.5
MultimodalGrok 4.2070.1Margin→ 8.4Kimi K2.578.5
AgenticGrok 4.2047.1Margin→ 7.9Kimi K2.555.0
ReasoningGrok 4.2053.3Margin→ 7.7Kimi K2.561.0
CodingGrok 4.2067.1Margin← 7.7Kimi K2.559.4
KnowledgeGrok 4.20Not measuredMarginNo overlapKimi K2.556.9
MathGrok 4.20Not measuredMarginNo overlapKimi K2.560.6
MultilingualGrok 4.20Not measuredMarginNo overlapKimi K2.582.3
Inst. FollowingGrok 4.20Not measuredMarginNo overlapKimi K2.593.9

Decisive benchmark drivers

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

More
A · Grok 4.20B · Kimi K2.5

  1. Terminal-Bench 2.0

    Agentic
    Source ↗
    A 47.1%B 50.8%
    Winner: Kimi K2.5Δ 3.7
    Terminal-Bench 2.0: Grok 4.20 scored 47.1%; Kimi K2.5 scored 50.8%. Kimi K2.5 wins this benchmark.

  2. MMMU-Pro

    Multimodal
    Source ↗
    A 75.2%B 78.5%
    Winner: Kimi K2.5Δ 3.3
    MMMU-Pro: Grok 4.20 scored 75.2%; Kimi K2.5 scored 78.5%. Kimi K2.5 wins this benchmark.

  3. SWE-bench Pro

    Coding
    Source ↗
    A 51.8%B 50.7%
    Winner: Grok 4.20Δ 1.1
    SWE-bench Pro: Grok 4.20 scored 51.8%; Kimi K2.5 scored 50.7%. Grok 4.20 wins this benchmark.

  4. SWE-bench Verified

    Coding
    Source ↗
    A 76.7%B 76.8%
    Winner: Kimi K2.5Δ 0.1
    SWE-bench Verified: Grok 4.20 scored 76.7%; Kimi K2.5 scored 76.8%. Kimi K2.5 wins this benchmark.

Operational comparison

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

MetricGrok 4.20Kimi K2.5Comparison
Input / output priceUSD per 1M tokensGrok 4.20$2 input / $6 outputKimi K2.5$0.6 input / $3 outputKimi K2.5 has the lower combined listed price.
Generation speedtokens per secondGrok 4.20233 tok/sKimi K2.545 tok/sGrok 4.20 has the higher measured throughput.
First-answer latencyseconds to first tokenGrok 4.2010.33 sKimi K2.52.38 sKimi K2.5 reaches the first token sooner.
Context windowmaximum listed tokensGrok 4.202MKimi K2.5256KGrok 4.20 lists the larger context window.

Benchmark Deep Dive

AgenticKimi K2.5 wins
BenchmarkGrok 4.20Kimi K2.5Result
Terminal-Bench 2.0Source 47.1%50.8%Kimi K2.5 leads
DeepSearchQASource 62.8%77.1%Kimi K2.5 leads
Gert LabsSource 38.36%45.88%Kimi K2.5 leads
BrowseCompSource —60.6%Not comparable
Claw-EvalSource —52.3%Not comparable
QwenClawBenchSource —54.3%Not comparable
τ³-bench resultsSource —65.7%Not comparable
DeepPlanningSource —14.4%Not comparable
ToolathlonSource —27.8%Not comparable
MCP AtlasSource —29.5%Not comparable
MCP-TasksSource —59.1%Not comparable
WideResearchSource —72.7%Not comparable
τ²-bench resultsSource —95.9%Not comparable
APEX-Agents-AASource —11.5%Not comparable
ResearchClawBenchSource —14.0%Not comparable
JobBenchSource —8.7%Not comparable
AA Agentic IndexSource —21.7%Not comparable
GDPval-AASource —25.1%Not comparable
GDPval-AASource —1003Not comparable
CodingGrok 4.20 wins
BenchmarkGrok 4.20Kimi K2.5Result
LiveCodeBench ProSource 74.2%—Not comparable
SWE-bench VerifiedSource 76.7%76.8%Kimi K2.5 leads
SWE-bench ProSource 51.8%50.7%Grok 4.20 leads
Vibe Code BenchSource 4.06%—Not comparable
SWE-bench Verified*Source —70.8%Not comparable
LiveCodeBench v6Source —85.0%Not comparable
SWE MultilingualSource —73%Not comparable
SWE-RebenchSource —58.5%Not comparable
React Native EvalsSource —77.2%Not comparable
SciCodeSource —48.7%Not comparable
AA-SciCodeSource —49.0%Not comparable
AA Coding IndexSource —46.8%Not comparable
ReasoningKimi K2.5 wins
BenchmarkGrok 4.20Kimi K2.5Result
ARC-AGI-2Source 53.3%—Not comparable
ARC-AGI-3Source 0.1%—Not comparable
LongBench v2Source —61%Not comparable
AA-LCRSource —65.3%Not comparable
CritPtSource —3.1%Not comparable
Knowledge
BenchmarkGrok 4.20Kimi K2.5Result
GPQA-DSource 88.5%87.6%Grok 4.20 leads
HLE w/o toolsSource 31.6%—Not comparable
HealthBench HardSource 20.3%—Not comparable
MedXpertQA (Text)Source 50.2%—Not comparable
GPQASource —87.6%Not comparable
SuperGPQASource —69.2%Not comparable
MMLU-ProSource —87.1%Not comparable
MMLU-Pro (Arcee)Source —87.1%Not comparable
HLESource —30.1%Not comparable
Artificial Analysis Intelligence IndexSource —35.4%Not comparable
AA-GPQA DiamondSource —87.9%Not comparable
AA-HLESource —29.4%Not comparable
AA-Omniscience IndexSource —-8.1%Not comparable
AA-Omniscience AccuracySource —34.3%Not comparable
AA-Omniscience Hallucination RateSource —64.6%Not comparable
Math
BenchmarkGrok 4.20Kimi K2.5Result
AIME 2025Source —96.1%Not comparable
AIME26Source —95.8%Not comparable
AIME25 (Arcee)Source —96.3%Not comparable
HMMT Feb 2025Source —95.4%Not comparable
HMMT Nov 2025Source —91.1%Not comparable
HMMT Feb 2026Source —87.1%Not comparable
MMAnswerBenchSource —81.8%Not comparable
FrontierMath v2 (Tiers 1-3)Source —27.900%Not comparable
FrontierMath v2 (Tier 4)Source —4.200%Not comparable
Multilingual
BenchmarkGrok 4.20Kimi K2.5Result
MMLU-ProXSource —82.3%Not comparable
NOVA-63Source —56.0%Not comparable
MultimodalKimi K2.5 wins
BenchmarkGrok 4.20Kimi K2.5Result
MMMU-ProSource 75.2%78.5%Kimi K2.5 leads
CharXivSource 60.9%—Not comparable
ERQASource 54.1%—Not comparable
SimpleVQASource 57.4%—Not comparable
MedXpertQA (MM)Source 65.8%—Not comparable
Design Arena WebsiteSource 12521275Kimi K2.5 leads
Video-MMESource —87.4%Not comparable
MMVUSource —80.4%Not comparable
VideoMMMUSource —86.6%Not comparable
AA-MMMU-ProSource —75.4%Not comparable
Inst. Following
BenchmarkGrok 4.20Kimi K2.5Result
IFEvalSource —93.9%Not comparable
AA-IFBenchSource —70.2%Not comparable
Frequently Asked Questions (5)

Which is better, Grok 4.20 or Kimi K2.5?

Kimi K2.5 is ahead on BenchLM's BenchAlign leaderboard, 58.78 to 53.88. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 47.1% and 50.8%.

Which is better for coding, Grok 4.20 or Kimi K2.5?

Grok 4.20 has the edge for coding in this comparison, averaging 67.1 versus 59.4. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.

Which is better for reasoning, Grok 4.20 or Kimi K2.5?

Kimi K2.5 has the edge for reasoning in this comparison, averaging 61 versus 53.3. Grok 4.20 stays close enough that the answer can still flip depending on your workload.

Which is better for agentic tasks, Grok 4.20 or Kimi K2.5?

Kimi K2.5 has the edge for agentic tasks in this comparison, averaging 55 versus 47.1. Inside this category, DeepSearchQA is the benchmark that creates the most daylight between them.

Which is better for multimodal and grounded tasks, Grok 4.20 or Kimi K2.5?

Kimi K2.5 has the edge for multimodal and grounded tasks in this comparison, averaging 78.5 versus 70.1. Inside this category, Design Arena Website 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.

Grok 4.20
API / mo$6,000
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Kimi K2.5
API / mo$2,700
Self-host / mo$5,221
Break-even132M/day
Model the full break-even

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