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Model comparison

GPT-5.1-Codex-Max vs Kimi K2.5

Data verified

Head-to-head evidence from 12 shared benchmark results across 6 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

54.48/100
Margin
5.2pts
winning →
Kimi K2.5
Moonshot AI
59.66/100
0 category wins0 category wins

Public leaderboard positions: GPT-5.1-Codex-Max #90 (Estimated); Kimi K2.5 #54 (Supported). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.1-Codex-Max and Kimi K2.5 share 12 comparable benchmark results. 0 of 8 categories are comparable. 1 result is unique to GPT-5.1-Codex-Max; 51 to Kimi K2.5.

Updated July 20, 2026
Shared results
12
GPT-5.1-Codex-Max only
1
Kimi K2.5 only
51
Comparable categories
0 / 8

Benchmark data for GPT-5.1-Codex-Max and Kimi K2.5 is coming soon on BenchLM.

Confidence note. This is a partial-evidence comparison with 12 shared benchmark results across 6 evidence categories; 0 of 8 categories currently have scoreable aggregates for both models. Treat the verdict as directional until coverage is more balanced.

Why this result

BenchLM has partial data for these models, but not enough overlapping benchmark coverage to produce a fair score-level comparison yet.

GPT-5.1-Codex-Max is priced at $1.25 input / $10.00 output per 1M tokens, versus $0.60 input / $3.00 output per 1M tokens for Kimi K2.5. GPT-5.1-Codex-Max has the larger context window at 400K, 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-5.1-Codex-Max and Kimi K2.5
CategoryGPT-5.1-Codex-MaxΔKimi K2.5
AgenticGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.555.0
CodingGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.559.4
ReasoningGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.561.0
KnowledgeGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.556.9
MathGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.560.6
MultilingualGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.582.3
MultimodalGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.578.5
Inst. FollowingGPT-5.1-Codex-MaxNot measuredMarginNo overlapKimi K2.593.9

Operational comparison

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

MetricGPT-5.1-Codex-MaxKimi K2.5Comparison
Input / output priceUSD per 1M tokensGPT-5.1-Codex-Max$1.25 input / $10 outputKimi K2.5$0.6 input / $3 outputKimi K2.5 has the lower combined listed price.
Generation speedtokens per secondGPT-5.1-Codex-MaxNot availableKimi K2.545 tok/sA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.1-Codex-MaxNot availableKimi K2.52.38 sA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.1-Codex-Max400KKimi K2.5256KGPT-5.1-Codex-Max lists the larger context window.

Benchmark Deep Dive

Agentic
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
τ²-bench resultsSource 83%95.9%Kimi 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
AA Agentic IndexSource —21.7%Not comparable
GDPval-AASource —25.4%Not comparable
GDPval-AASource —1009Not comparable
Coding
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
Vibe Code BenchSource 22.17%—Not comparable
AA-SciCodeSource 40.2%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
AA Coding IndexSource —46.8%Not comparable
Reasoning
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
AA-LCRSource 67.3%65.3%GPT-5.1-Codex-Max leads
CritPtSource 5.7%3.1%GPT-5.1-Codex-Max leads
LongBench v2Source —61%Not comparable
Knowledge
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
Artificial Analysis Intelligence IndexSource 34.7%35.4%Kimi K2.5 leads
AA-GPQA DiamondSource 86.0%87.9%Kimi K2.5 leads
AA-HLESource 23.4%29.4%Kimi K2.5 leads
AA-Omniscience IndexSource -6.0%-8.1%GPT-5.1-Codex-Max leads
AA-Omniscience AccuracySource 39.2%34.3%GPT-5.1-Codex-Max leads
AA-Omniscience Hallucination RateSource 74.4%64.6%Kimi K2.5 leads
GPQASource —87.6%Not comparable
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
Math
BenchmarkGPT-5.1-Codex-MaxKimi 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
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
MMLU-ProXSource —82.3%Not comparable
NOVA-63Source —56.0%Not comparable
Multimodal
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
AA-MMMU-ProSource 72.5%75.4%Kimi 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
Design Arena WebsiteSource —1282Not comparable
Inst. Following
BenchmarkGPT-5.1-Codex-MaxKimi K2.5Result
AA-IFBenchSource 70.0%70.2%Kimi K2.5 leads
IFEvalSource —93.9%Not comparable
Frequently Asked Questions (3)

Can I compare GPT-5.1-Codex-Max and Kimi K2.5 on BenchLM yet?

Not fully yet. BenchLM is tracking both models, but the sourced benchmark breakdown for this comparison is still coming soon.

Why does this comparison show “coming soon”?

BenchLM only shows category winners and benchmark-level calls when we have sourced results that can be compared fairly. For these models, the public benchmark coverage is not complete enough yet.

What data is available for GPT-5.1-Codex-Max and Kimi K2.5 today?

GPT-5.1-Codex-Max: $1.25 input / $10.00 output per 1M tokens Kimi K2.5: $0.60 input / $3.00 output per 1M tokens Both model pages still include creator, context window, reasoning mode, and other metadata while benchmark coverage fills in.

Self-host vs API cost

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

GPT-5.1-Codex-Max
API / mo$8,438
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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