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Model comparison

GPT-4.1 vs Kimi K2.5 (Reasoning)

Data verified

Head-to-head evidence from 16 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

OpenAI
50.44/100
Margin
8.2pts
winning →
58.61/100
0 category wins2 category wins

Public leaderboard positions: GPT-4.1 #111 (Supported); Kimi K2.5 (Reasoning) #63 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-4.1 and Kimi K2.5 (Reasoning) share 16 comparable benchmark results. 2 of 8 categories are comparable. 4 results are unique to GPT-4.1; 11 to Kimi K2.5 (Reasoning).

Updated July 24, 2026
Shared results
16
GPT-4.1 only
4
Kimi K2.5 (Reasoning) only
11
Comparable categories
2 / 8

Pick Kimi K2.5 (Reasoning) if you want the stronger benchmark profile. GPT-4.1 only becomes the better choice if you need the larger 1M context window or you would rather avoid the extra latency and token burn of a reasoning model.

Confidence note. This is a partial-evidence comparison with 16 shared benchmark results across 6 evidence categories; 2 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 (Reasoning) is clearly ahead on the BenchAlign aggregate, 58.61 to 50.44. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

Kimi K2.5 (Reasoning)'s sharpest advantage is in coding, where it averages 76.8 against 54.6. The single biggest benchmark swing on the page is SWE-bench Verified, 54.6% to 76.8%.

GPT-4.1 is also the more expensive model on tokens at $2.00 input / $8.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5 (Reasoning). That is roughly 2.7x on output cost alone. Kimi K2.5 (Reasoning) is the reasoning model in the pair, while GPT-4.1 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. GPT-4.1 gives you the larger context window at 1M, compared with 128K for Kimi K2.5 (Reasoning).

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 and Kimi K2.5 (Reasoning)
CategoryGPT-4.1ΔKimi K2.5 (Reasoning)
CodingGPT-4.154.6Margin 22.2Kimi K2.5 (Reasoning)76.8
KnowledgeGPT-4.166.3Margin 20.9Kimi K2.5 (Reasoning)87.2
AgenticGPT-4.1Not measuredMarginNo overlapKimi K2.5 (Reasoning)55.0
MathGPT-4.14.1MarginNo overlapKimi K2.5 (Reasoning)Not measured
MultimodalGPT-4.1Not measuredMarginNo overlapKimi K2.5 (Reasoning)78.5
Inst. FollowingGPT-4.187.4MarginNo overlapKimi K2.5 (Reasoning)Not measured

Decisive benchmark drivers

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

More
A · GPT-4.1B · Kimi K2.5 (Reasoning)
  1. SWE-bench Verified

    Coding
    Source ↗
    A 54.6%B 76.8%
    Winner: Kimi K2.5 (Reasoning)Δ 22.2
    SWE-bench Verified: GPT-4.1 scored 54.6%; Kimi K2.5 (Reasoning) scored 76.8%. Kimi K2.5 (Reasoning) wins this benchmark.
  2. GPQA

    Knowledge
    Source ↗
    A 66.3%B 87.6%
    Winner: Kimi K2.5 (Reasoning)Δ 21.3
    GPQA: GPT-4.1 scored 66.3%; Kimi K2.5 (Reasoning) scored 87.6%. Kimi K2.5 (Reasoning) wins this benchmark.

Operational comparison

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

MetricGPT-4.1Kimi K2.5 (Reasoning)Comparison
Input / output priceUSD per 1M tokensGPT-4.1$2 input / $8 outputKimi K2.5 (Reasoning)$0.6 input / $3 outputKimi K2.5 (Reasoning) has the lower combined listed price.
Generation speedtokens per secondGPT-4.1108 tok/sKimi K2.5 (Reasoning)Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-4.11.02 sKimi K2.5 (Reasoning)Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-4.11MKimi K2.5 (Reasoning)128KGPT-4.1 lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
τ²-bench resultsSource 47.1%95.9%Kimi K2.5 (Reasoning) leads
Gert LabsSource 25.65%32.58%Kimi K2.5 (Reasoning) leads
Terminal-Bench 2.0Source 50.8%Not comparable
BrowseCompSource 60.6%Not comparable
APEX-Agents-AASource 11.5%Not comparable
AA Agentic IndexSource 21.7%Not comparable
GDPval-AASource 25.1%Not comparable
GDPval-AASource 1003Not comparable
CodingKimi K2.5 (Reasoning) wins
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
SWE-bench VerifiedSource 54.6%76.8%Kimi K2.5 (Reasoning) leads
AA-SciCodeSource 38.1%49.0%Kimi K2.5 (Reasoning) leads
Vibe Code BenchSource 17.54%Not comparable
AA Coding IndexSource 46.8%Not comparable
Reasoning
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
AA-LCRSource 61.0%65.3%Kimi K2.5 (Reasoning) leads
CritPtSource 0.0%3.1%Kimi K2.5 (Reasoning) leads
KnowledgeKimi K2.5 (Reasoning) wins
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
MMLUSource 90.2%Not comparable
GPQASource 66.3%87.6%Kimi K2.5 (Reasoning) leads
Artificial Analysis Intelligence IndexSource 19.4%35.4%Kimi K2.5 (Reasoning) leads
AA-GPQA DiamondSource 66.6%87.9%Kimi K2.5 (Reasoning) leads
AA-HLESource 4.6%29.4%Kimi K2.5 (Reasoning) leads
AA-Omniscience IndexSource -36.2%-8.1%Kimi K2.5 (Reasoning) leads
AA-Omniscience AccuracySource 24.2%34.3%Kimi K2.5 (Reasoning) leads
AA-Omniscience Hallucination RateSource 79.6%64.6%Kimi K2.5 (Reasoning) leads
MMLU-ProSource 87.1%Not comparable
Math
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
FrontierMath v2 (Tiers 1-3)Source 5.517%Not comparable
FrontierMath v2 (Tier 4)Source 0.000%Not comparable
AIME 2025Source 96.1%Not comparable
Multimodal
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
AA-MMMU-ProSource 61.2%75.4%Kimi K2.5 (Reasoning) leads
Design Arena WebsiteSource 10681279Kimi K2.5 (Reasoning) leads
MMMU-ProSource 78.5%Not comparable
Inst. Following
BenchmarkGPT-4.1Kimi K2.5 (Reasoning)Result
IFEvalSource 87.4%Not comparable
AA-IFBenchSource 43.0%70.2%Kimi K2.5 (Reasoning) leads
Frequently Asked Questions (3)

Which is better, GPT-4.1 or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) is ahead on BenchLM's BenchAlign leaderboard, 58.61 to 50.44. The biggest single separator in this matchup is SWE-bench Verified, where the scores are 54.6% and 76.8%.

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

Kimi K2.5 (Reasoning) has the edge for knowledge tasks in this comparison, averaging 87.2 versus 66.3. Inside this category, AA-Omniscience Index is the benchmark that creates the most daylight between them.

Which is better for coding, GPT-4.1 or Kimi K2.5 (Reasoning)?

Kimi K2.5 (Reasoning) has the edge for coding in this comparison, averaging 76.8 versus 54.6. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.

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Last updated: July 24, 2026