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Model comparison

GPT-4.1 nano vs Kimi K2.5

Data verified

Head-to-head evidence from 20 shared benchmark results across 7 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

42.06/100
Margin
17.6pts
winning →
Kimi K2.5
Moonshot AI
59.66/100
0 category wins3 category wins

Public leaderboard positions: GPT-4.1 nano #161 (Estimated); Kimi K2.5 #54 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-4.1 nano and Kimi K2.5 share 20 comparable benchmark results. 3 of 8 categories are comparable. 1 result is unique to GPT-4.1 nano; 43 to Kimi K2.5.

Updated July 23, 2026
Shared results
20
GPT-4.1 nano only
1
Kimi K2.5 only
43
Comparable categories
3 / 8

Pick Kimi K2.5 if you want the stronger benchmark profile. GPT-4.1 nano only becomes the better choice if you want the cheaper token bill or you need the larger 1M context window.

Confidence note. This is a partial-evidence comparison with 20 shared benchmark results across 7 evidence categories; 3 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, 59.66 to 42.06. 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 mathematics, where it averages 60.6 against 1. The single biggest benchmark swing on the page is GPQA, 50.3% to 87.6%.

Kimi K2.5 is also the more expensive model on tokens at $0.60 input / $3.00 output per 1M tokens, versus $0.10 input / $0.40 output per 1M tokens for GPT-4.1 nano. That is roughly 7.5x on output cost alone. GPT-4.1 nano gives you the larger context window at 1M, 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 GPT-4.1 nano and Kimi K2.5
CategoryGPT-4.1 nanoΔKimi K2.5
MathGPT-4.1 nano1.0Margin→ 59.6Kimi K2.560.6
Inst. FollowingGPT-4.1 nano83.2Margin→ 10.7Kimi K2.593.9
KnowledgeGPT-4.1 nano50.3Margin→ 6.6Kimi K2.556.9
AgenticGPT-4.1 nanoNot measuredMarginNo overlapKimi K2.555.0
CodingGPT-4.1 nanoNot measuredMarginNo overlapKimi K2.559.4
ReasoningGPT-4.1 nanoNot measuredMarginNo overlapKimi K2.561.0
MultilingualGPT-4.1 nanoNot measuredMarginNo overlapKimi K2.582.3
MultimodalGPT-4.1 nanoNot measuredMarginNo overlapKimi K2.578.5

Decisive benchmark drivers

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

More
A · GPT-4.1 nanoB · Kimi K2.5

  1. GPQA

    Knowledge
    Source ↗
    A 50.3%B 87.6%
    Winner: Kimi K2.5Δ 37.3
    GPQA: GPT-4.1 nano scored 50.3%; Kimi K2.5 scored 87.6%. Kimi K2.5 wins this benchmark.

  2. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 1.034%B 27.900%
    Winner: Kimi K2.5Δ 26.9
    FrontierMath v2 (Tiers 1-3): GPT-4.1 nano scored 1.034%; Kimi K2.5 scored 27.900%. Kimi K2.5 wins this benchmark.

  3. IFEval

    Inst. Following
    Source ↗
    A 83.2%B 93.9%
    Winner: Kimi K2.5Δ 10.7
    IFEval: GPT-4.1 nano scored 83.2%; Kimi K2.5 scored 93.9%. Kimi K2.5 wins this benchmark.

Operational comparison

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

MetricGPT-4.1 nanoKimi K2.5Comparison
Input / output priceUSD per 1M tokensGPT-4.1 nano$0.1 input / $0.4 outputKimi K2.5$0.6 input / $3 outputGPT-4.1 nano has the lower combined listed price.
Generation speedtokens per secondGPT-4.1 nano181 tok/sKimi K2.545 tok/sGPT-4.1 nano has the higher measured throughput.
First-answer latencyseconds to first tokenGPT-4.1 nano0.63 sKimi K2.52.38 sGPT-4.1 nano reaches the first token sooner.
Context windowmaximum listed tokensGPT-4.1 nano1MKimi K2.5256KGPT-4.1 nano lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-4.1 nanoKimi K2.5Result
AA Agentic IndexSource 1.2%21.7%Kimi K2.5 leads
τ²-bench resultsSource 17.3%95.9%Kimi K2.5 leads
GDPval-AASource 0.0%25.4%Kimi K2.5 leads
GDPval-AASource 411009Kimi K2.5 leads
Terminal-Bench 2.0Source —50.8%Not comparable
BrowseCompSource —60.6%Not comparable
Claw-EvalSource —52.3%Not comparable
QwenClawBenchSource —54.3%Not comparable
τ³-bench resultsSource —65.7%Not comparable
DeepSearchQASource —77.1%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
APEX-Agents-AASource —11.5%Not comparable
Gert LabsSource —45.88%Not comparable
ResearchClawBenchSource —14.0%Not comparable
JobBenchSource —8.7%Not comparable
Coding
BenchmarkGPT-4.1 nanoKimi K2.5Result
AA Coding IndexSource 11.1%46.8%Kimi K2.5 leads
AA-SciCodeSource 25.9%49.0%Kimi K2.5 leads
SWE-bench VerifiedSource —76.8%Not comparable
SWE-bench Verified*Source —70.8%Not comparable
LiveCodeBench v6Source —85.0%Not comparable
SWE-bench ProSource —50.7%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
Reasoning
BenchmarkGPT-4.1 nanoKimi K2.5Result
AA-LCRSource 17.0%65.3%Kimi K2.5 leads
CritPtSource 0.0%3.1%Kimi K2.5 leads
LongBench v2Source —61%Not comparable
KnowledgeKimi K2.5 wins
BenchmarkGPT-4.1 nanoKimi K2.5Result
MMLUSource 80.1%—Not comparable
GPQASource 50.3%87.6%Kimi K2.5 leads
Artificial Analysis Intelligence IndexSource 9.6%35.4%Kimi K2.5 leads
AA-GPQA DiamondSource 51.2%87.9%Kimi K2.5 leads
AA-HLESource 3.9%29.4%Kimi K2.5 leads
AA-Omniscience IndexSource -56.4%-8.1%Kimi K2.5 leads
AA-Omniscience AccuracySource 13.3%34.3%Kimi K2.5 leads
AA-Omniscience Hallucination RateSource 80.4%64.6%Kimi K2.5 leads
GPQA-DSource —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
MathKimi K2.5 wins
BenchmarkGPT-4.1 nanoKimi K2.5Result
FrontierMath v2 (Tiers 1-3)Source 1.034%27.900%Kimi K2.5 leads
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 (Tier 4)Source —4.200%Not comparable
Multilingual
BenchmarkGPT-4.1 nanoKimi K2.5Result
MMLU-ProXSource —82.3%Not comparable
NOVA-63Source —56.0%Not comparable
Multimodal
BenchmarkGPT-4.1 nanoKimi K2.5Result
AA-MMMU-ProSource 40.1%75.4%Kimi K2.5 leads
Design Arena WebsiteSource 10031279Kimi K2.5 leads
MMMU-ProSource —78.5%Not comparable
Video-MMESource —87.4%Not comparable
MMVUSource —80.4%Not comparable
VideoMMMUSource —86.6%Not comparable
Inst. FollowingKimi K2.5 wins
BenchmarkGPT-4.1 nanoKimi K2.5Result
IFEvalSource 83.2%93.9%Kimi K2.5 leads
AA-IFBenchSource 32.0%70.2%Kimi K2.5 leads
Frequently Asked Questions (4)

Which is better, GPT-4.1 nano or Kimi K2.5?

Kimi K2.5 is ahead on BenchLM's BenchAlign leaderboard, 59.66 to 42.06. The biggest single separator in this matchup is GPQA, where the scores are 50.3% and 87.6%.

Which is better for knowledge tasks, GPT-4.1 nano or Kimi K2.5?

Kimi K2.5 has the edge for knowledge tasks in this comparison, averaging 56.9 versus 50.3. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.

Which is better for math, GPT-4.1 nano or Kimi K2.5?

Kimi K2.5 has the edge for math in this comparison, averaging 60.6 versus 1. Inside this category, FrontierMath v2 (Tiers 1-3) is the benchmark that creates the most daylight between them.

Which is better for instruction following, GPT-4.1 nano or Kimi K2.5?

Kimi K2.5 has the edge for instruction following in this comparison, averaging 93.9 versus 83.2. Inside this category, AA-IFBench 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.

GPT-4.1 nano
API / mo$375
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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