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Model comparison

GPT-5.5 Pro vs Kimi K2.6

Data verified

Head-to-head evidence from 5 shared benchmark results across 4 categories. Overall scores shown here use the public BenchAlign v5 ranking lane.

63.69/100
Margin
6.9pts
← winning
Kimi K2.6
Moonshot AI
56.79/100
2 category wins1 category wins

Public leaderboard positions: GPT-5.5 Pro #38 (Estimated); Kimi K2.6 #74 (Estimated). Intervals and evidence labels describe ranking uncertainty, not a guarantee for a specific workload.

Evidence parity. GPT-5.5 Pro and Kimi K2.6 share 5 comparable benchmark results. 3 of 8 categories are comparable. 2 results are unique to GPT-5.5 Pro; 46 to Kimi K2.6.

Updated July 23, 2026
Shared results
5
GPT-5.5 Pro only
2
Kimi K2.6 only
46
Comparable categories
3 / 8

Pick GPT-5.5 Pro if you want the stronger benchmark profile. Kimi K2.6 only becomes the better choice if mathematics is the priority or you want the cheaper token bill.

Confidence note. This is a partial-evidence comparison with 5 shared benchmark results across 4 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

GPT-5.5 Pro is clearly ahead on the BenchAlign aggregate, 63.69 to 56.79. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.

GPT-5.5 Pro's sharpest advantage is in agentic, where it averages 90.1 against 73.5. The single biggest benchmark swing on the page is FrontierMath v2 (Tier 4), 39.600% to 14.580%. Kimi K2.6 does hit back in mathematics, so the answer changes if that is the part of the workload you care about most.

GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $0.95 input / $4.00 output per 1M tokens for Kimi K2.6. That is roughly 45.0x on output cost alone. GPT-5.5 Pro gives you the larger context window at 1M, compared with 256K 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 GPT-5.5 Pro and Kimi K2.6
CategoryGPT-5.5 ProΔKimi K2.6
MathGPT-5.5 Pro48.1Margin→ 19.0Kimi K2.667.1
AgenticGPT-5.5 Pro90.1Margin← 16.6Kimi K2.673.5
KnowledgeGPT-5.5 Pro57.2Margin← 15.0Kimi K2.642.2
CodingGPT-5.5 ProNot measuredMarginNo overlapKimi K2.664.4
MultimodalGPT-5.5 ProNot measuredMarginNo overlapKimi K2.679.8

Decisive benchmark drivers

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

More
A · GPT-5.5 ProB · Kimi K2.6

  1. FrontierMath v2 (Tier 4)

    Math
    Source ↗
    A 39.600%B 14.580%
    Winner: GPT-5.5 ProΔ 25
    FrontierMath v2 (Tier 4): GPT-5.5 Pro scored 39.600%; Kimi K2.6 scored 14.580%. GPT-5.5 Pro wins this benchmark.

  2. HLE

    Knowledge
    Source ↗
    A 57.2%B 34.7%
    Winner: GPT-5.5 ProΔ 22.5
    HLE: GPT-5.5 Pro scored 57.2%; Kimi K2.6 scored 34.7%. GPT-5.5 Pro wins this benchmark.

  3. FrontierMath v2 (Tiers 1-3)

    Math
    Source ↗
    A 51.000%B 38.966%
    Winner: GPT-5.5 ProΔ 12
    FrontierMath v2 (Tiers 1-3): GPT-5.5 Pro scored 51.000%; Kimi K2.6 scored 38.966%. GPT-5.5 Pro wins this benchmark.

  4. BrowseComp

    Agentic
    Source ↗
    A 90.1%B 83.2%
    Winner: GPT-5.5 ProΔ 6.9
    BrowseComp: GPT-5.5 Pro scored 90.1%; Kimi K2.6 scored 83.2%. GPT-5.5 Pro wins this benchmark.

Operational comparison

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

MetricGPT-5.5 ProKimi K2.6Comparison
Input / output priceUSD per 1M tokensGPT-5.5 Pro$30 input / $180 outputKimi K2.6$0.95 input / $4 outputKimi K2.6 has the lower combined listed price.
Generation speedtokens per secondGPT-5.5 ProNot availableKimi K2.6Not availableA complete speed comparison is not available.
First-answer latencyseconds to first tokenGPT-5.5 ProNot availableKimi K2.6Not availableA complete latency comparison is not available.
Context windowmaximum listed tokensGPT-5.5 Pro1MKimi K2.6256KGPT-5.5 Pro lists the larger context window.

Benchmark Deep Dive

AgenticGPT-5.5 Pro wins
BenchmarkGPT-5.5 ProKimi K2.6Result
BrowseCompSource 90.1%83.2%GPT-5.5 Pro leads
Terminal-Bench 2.0Source —66.7%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%Not comparable
τ²-bench resultsSource —95.9%Not comparable
GDPval-AASource —34.5%Not comparable
GDPval-AASource —1189Not comparable
APEX-Agents-AASource —28.5%Not comparable
Gert LabsSource —56.82%Not comparable
ResearchClawBenchSource —18.0%Not comparable
OSWorld 2.0Source —4.6%Not comparable
terminalBenchHardSource —43.9%Not comparable
Coding
BenchmarkGPT-5.5 ProKimi K2.6Result
SWE-bench VerifiedSource —80.2%Not comparable
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%Not comparable
AA-SciCodeSource —53.5%Not comparable
Reasoning
BenchmarkGPT-5.5 ProKimi K2.6Result
CritPtSource 30.6%8.0%GPT-5.5 Pro leads
AA-LCRSource —69.7%Not comparable
KnowledgeGPT-5.5 Pro wins
BenchmarkGPT-5.5 ProKimi K2.6Result
HLESource 57.2%34.7%GPT-5.5 Pro leads
HLE w/o toolsSource 43.1%—Not comparable
GPQASource —90.5%Not comparable
GPQA-DSource —90.5%Not comparable
Artificial Analysis Intelligence IndexSource —44.2%Not comparable
AA-GPQA DiamondSource —91.1%Not comparable
AA-HLESource —35.9%Not comparable
AA-Omniscience IndexSource —6.4%Not comparable
AA-Omniscience AccuracySource —32.8%Not comparable
AA-Omniscience Hallucination RateSource —39.3%Not comparable
MathKimi K2.6 wins
BenchmarkGPT-5.5 ProKimi K2.6Result
FrontierMath (legacy)Source 52.4%—Not comparable
FrontierMath v2 (Tiers 1-3)Source 51.000%38.966%GPT-5.5 Pro leads
FrontierMath v2 (Tier 4)Source 39.600%14.580%GPT-5.5 Pro leads
AIME26Source —96.4%Not comparable
HMMT Feb 2026Source —92.7%Not comparable
MMAnswerBenchSource —86.0%Not comparable
Multimodal
BenchmarkGPT-5.5 ProKimi K2.6Result
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%Not comparable
Design Arena WebsiteSource —1306Not comparable
Inst. Following
BenchmarkGPT-5.5 ProKimi K2.6Result
AA-IFBenchSource —76.0%Not comparable
Frequently Asked Questions (4)

Which is better, GPT-5.5 Pro or Kimi K2.6?

GPT-5.5 Pro is ahead on BenchLM's BenchAlign leaderboard, 63.69 to 56.79. The biggest single separator in this matchup is FrontierMath v2 (Tier 4), where the scores are 39.600% and 14.580%.

Which is better for knowledge tasks, GPT-5.5 Pro or Kimi K2.6?

GPT-5.5 Pro has the edge for knowledge tasks in this comparison, averaging 57.2 versus 42.2. Inside this category, HLE is the benchmark that creates the most daylight between them.

Which is better for math, GPT-5.5 Pro or Kimi K2.6?

Kimi K2.6 has the edge for math in this comparison, averaging 67.1 versus 48.1. Inside this category, FrontierMath v2 (Tier 4) is the benchmark that creates the most daylight between them.

Which is better for agentic tasks, GPT-5.5 Pro or Kimi K2.6?

GPT-5.5 Pro has the edge for agentic tasks in this comparison, averaging 90.1 versus 73.5. Inside this category, BrowseComp 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-5.5 Pro
API / mo$157,500
Self-host / moNot listed
Break-even—
Proprietary model — self-hosting not applicable.
Kimi K2.6
API / mo$3,713
Self-host / mo$18,221
Break-even326M/day
Model the full break-even

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