Head-to-head comparison

GPT-5.5 vs. Kimi K2.6

Compare published benchmark results from matching versions and cohorts, API pricing, and technical specifications. Any documented test setup differences remain visible.

shared result series: 233
distinct benchmarks: 26
latest retrieval: 2026-09-04

First modelSecond model

Specifications

General specifications

Release date, availability, context window, architecture, and published parameter counts at a glance. Undisclosed details remain marked as unavailable.

Specifications for GPT-5.5 and Kimi K2.6
Attribute	GPT-5.5	Kimi K2.6
Provider	OpenAI	Moonshot AI
Released	Apr 2026	Apr 20, 2026
Availability	Active	Active
Model type	Proprietary	Open Weights
Parameters	Not published	1T, 32B active
Architecture	Not published	Mixture of Experts
Context window	1,050,000 tokens	262,144 tokens
Knowledge cutoff	December 1, 2025	Not published
Technical sources	Model	Model, Context

Pricing

API pricing compared

The table compares official standard API rates per 1M tokens, including published cache pricing. Batch, fast, priority, regional surcharges, tool calls, and cloud platform pricing are excluded.

API pricing for GPT-5.5 and Kimi K2.6
Price type	GPT-5.5	Kimi K2.6
API input	$5 ≤272K / $10 >272K	$0.95
API output	$30 ≤272K / $45 >272K	$4
Cache read	$0.5 ≤272K / $1 >272K	$0.16
Cache write (5 min.)	Not listed	Not listed
Cache write (1 hr.)	Not listed	Not listed
Price verified	07/30/2026 Source	07/30/2026 Source

GPT-5.5Kimi K2.6

API inputUSD per 1M tokens, base tier

GPT-5.5$5

Kimi K2.6$0.95

API outputUSD per 1M tokens, base tier

GPT-5.5$30

Kimi K2.6$4

Cache readUSD per 1M tokens, base tier

GPT-5.5$0.5

Kimi K2.6$0.16

Key to the marks:better valuebetter, but not conclusivetie

Pricing by provider

Direct developer pricing and provider endpoint tariffs routed through OpenRouter are listed separately. Prices are in USD per 1M tokens. Context-dependent direct tiers plus regional, Flex, Priority, and other OpenRouter tariffs remain individually identifiable.

Provider pricing for GPT-5.5 and Kimi K2.6
Model	Provider	Purchase route and tariff	Input per 1M tokens	Output per 1M tokens	Source
GPT-5.5	OpenAI	Direct from developerUp to 272,000 context tokens	$5	$30	Source07/30/2026
	OpenAI	Direct from developerAbove 272,000 context tokens	$10	$45	Source07/30/2026
	Amazon Bedrock	Via OpenRouteramazon-bedrock/us-east-1	$5.5	$33	Source09/07/2026
	Azure	Via OpenRouterazure	$5	$30	Source09/07/2026
	Azure	Via OpenRouterazure/eu	$5.5	$33	Source09/07/2026
	Azure	Via OpenRouterazure/us	$5.5	$33	Source09/07/2026
	OpenAI	Via OpenRouteropenai	$5	$30	Source09/07/2026
	OpenAI	Via OpenRouteropenai/fast	$12.5	$75	Source09/07/2026
	OpenAI	Via OpenRouteropenai/flex	Lowest listed price: $2.5	Lowest listed price: $15	Source09/07/2026
Kimi K2.6	Moonshot AI	Direct from developerStandard API	$0.95	$4	Source07/30/2026
	AtlasCloud	Via OpenRouteratlas-cloud/int4	$0.95	$4	Source09/07/2026
	Baidu	Via OpenRouterbaidu/fp4	$0.95	$4	Source09/07/2026
	BaseTen	Via OpenRouterbaseten/fp4#1	$0.95	$4	Source09/07/2026
	BaseTen	Via OpenRouterbaseten/fp4#2	$0.95	$4	Source09/07/2026
	Chutes	Via OpenRouterchutes/int4	$0.58	$3.4	Source09/07/2026
	Cloudflare	Via OpenRoutercloudflare	$0.95	$4	Source09/07/2026
	CoreWeave	Via OpenRoutercoreweave/fp4	$0.65	$3.41	Source09/07/2026
	Crusoe	Via OpenRoutercrusoe/bf16	$0.7	$3.5	Source09/07/2026
	Decart	Via OpenRouterdecart/fp4	$0.5865	Lowest listed price: $2.4696	Source09/07/2026
	DeepInfra	Via OpenRouterdeepinfra/fp4	$0.75	$3.5	Source09/07/2026
	DigitalOcean	Via OpenRouterdigitalocean	$0.95	$4	Source09/07/2026
	Fireworks	Via OpenRouterfireworks	$0.95	$4	Source09/07/2026
	GMICloud	Via OpenRoutergmicloud/fp8	$0.855	$3.6	Source09/07/2026
	Inceptron	Via OpenRouterinceptron/int4	Lowest listed price: $0.56	$3.39	Source09/07/2026
	Moonshot AI	Via OpenRoutermoonshotai/int4	$0.95	$4	Source09/07/2026
	Novita	Via OpenRouternovita	$0.8	$3.4	Source09/07/2026
	Parasail	Via OpenRouterparasail/int4	$0.75	$3.5	Source09/07/2026
	Phala	Via OpenRouterphala	$1.09	$4.6	Source09/07/2026
	SiliconFlow	Via OpenRoutersiliconflow/fp8	$0.77	$3.4	Source09/07/2026
	StreamLake	Via OpenRouterstreamlake/fp8	$0.5985	$2.52	Source09/07/2026
	Venice	Via OpenRoutervenice/int4	$0.75	$3.5	Source09/07/2026

Performance

Shared benchmarks

Only published results with the same benchmark version, task, metric, and comparison cohort are paired. Different reasoning levels, agents, harnesses, or output limits appear directly in the table.

Capability profile from matched benchmarks

Each axis averages directly matched benchmark families. A value of 100 means the stronger value within this pair, not a universal quality score.

GPT-5.5

Kimi K2.6

Coding: 99.7 / 68 (6 benchmark families)

Reasoning: 100 / 97.4 (2 benchmark families)

Mathematics: 100 / 98.7 (1 benchmark family)

Knowledge: 100 / 99.4 (2 benchmark families)

Finance: 100 / 94.5 (6 benchmark families)

Legal: 100 / 70 (4 benchmark families)

Agentic tasks: 100 / 74.2 (1 benchmark family)

Multimodal: 100 / 97.8 (1 benchmark family)

58 matched rows from 25 benchmark families were considered. The radar shows 8 of 14 comparable categories.

GPT-5.5Kimi K2.6

Code MigrationOverall. Higher is better. No documented setup difference

GPT-5.545.161 %

Kimi K2.627.768 %

CorpFin v2Overall. Higher is better. No documented setup difference

GPT-5.568.415 %

Kimi K2.666.744 %

CyberBenchOverall. Higher is better. No documented setup difference

GPT-5.580.508 %

Kimi K2.674.351 %

EMBOverall. Higher is better. No documented setup difference

GPT-5.564.543 %

Kimi K2.657.855 %

Finance Agent (v2)Overall. Higher is better. No documented setup difference

GPT-5.551.76 %

Kimi K2.644.899 %

GPQA DiamondOverall. Higher is better. No documented setup difference

GPT-5.593.182 %

Kimi K2.689.142 %

Harvey's Legal Agent BenchmarkOverall · Task fully resolved. Higher is better. No documented setup difference

GPT-5.53.75 %

Kimi K2.61.667 %

Legal Research BenchOverall · All-pass. Higher is better. No documented setup difference

GPT-5.540.385 %

Kimi K2.615.865 %

LegalBenchOverall. Higher is better. No documented setup difference

GPT-5.586.515 %

Kimi K2.684.738 %

LiveCodeBench v6Overall. Higher is better. No documented setup difference

GPT-5.585.296 %

Kimi K2.686.771 %

LMArena Text, Style ControlOverall. Higher is better. No documented setup difference

GPT-5.51,477.235

Kimi K2.61,460.613

MedCodeOverall. Higher is better. No documented setup difference

GPT-5.549.1 %

Kimi K2.640.142 %

Key to the marks:better valuebetter, but not conclusivetie

Benchmark scores for GPT-5.5 and Kimi K2.6
Benchmark and task	GPT-5.5	Kimi K2.6	Source
Code MigrationOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner45.161 %	27.768 %	Vals AI Source details Data as of: 09/03/2026
CorpFin v2Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner68.415 %	66.744 %	Vals AI Source details Data as of: 08/12/2026
CyberBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner80.508 %	74.351 %	Vals AI Source details Data as of: 09/01/2026
EMBOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner64.543 %	57.855 %	Vals AI Source details Data as of: 09/03/2026
Finance Agent (v2)Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner51.76 %	44.899 %	Vals AI Source details Data as of: 09/03/2026
GPQA DiamondOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner93.182 %	89.142 %	Vals AI Source details Data as of: 09/01/2026
Harvey's Legal Agent BenchmarkOverall · Task fully resolved Test details No documented difference in the test setupVersion: 1Metric: task resolution rateScoring: Higher is better	Winner3.75 %	1.667 %	Vals AI Source details Data as of: 09/03/2026
Legal Research BenchOverall · All-pass Test details No documented difference in the test setupVersion: 1Metric: all-pass rateScoring: Higher is better	Winner40.385 %	15.865 %	Vals AI Source details Data as of: 09/03/2026
LegalBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner86.515 %	84.738 %	Vals AI Source details Data as of: 09/01/2026
LiveCodeBench v6Overall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	85.296 %	Winner86.771 %	Vals AI Source details Data as of: 09/01/2026
LMArena Text, Style ControlOverall Test details No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterGPT-5.5: Snapshot: gpt-5.5, Harness: Arena text, style control Kimi K2.6: Snapshot: kimi-k2.6, Harness: Arena text, style controlGPT-5.5: Style-controlled Arena rating from 64,686 anonymous pairwise votes.Kimi K2.6: Style-controlled Arena rating from 37,573 anonymous pairwise votes.	Winner1,477.235 95% confidence interval: ±3.839The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	1,460.613 95% confidence interval: ±4.534The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	LMArena Source details Data as of: 09/01/2026
MedCodeOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner49.1 %	40.142 %	Vals AI Source details Data as of: 09/03/2026
MedScribeOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner86.868 %	78.149 %	Vals AI Source details Data as of: 09/03/2026
MMLU-ProOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner88.144 %	87.572 %	Vals AI Source details Data as of: 09/01/2026
MMMU-ProOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner88.266 %	86.301 %	Vals AI Source details Data as of: 09/01/2026
MortgageTaxOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner68.76 %	65.818 %	Vals AI Source details Data as of: 09/01/2026
ProgramBenchOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner0.5 %	0 %	Vals AI Source details Data as of: 09/01/2026
Public Benefits Bench v1.1Overall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is better	Winner60.893 %	56.631 %	Vals AI Source details Data as of: 09/01/2026
SAGEOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner51.532 %	50.224 %	Vals AI Source details Data as of: 09/03/2026
SWE-bench VerifiedOverall Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner82.6 %	76.2 %	Vals AI Source details Data as of: 09/01/2026
TaxEval v2Overall Test details No documented difference in the test setupVersion: 2Metric: accuracyScoring: Higher is better	Winner74.98 %	74.652 %	Vals AI Source details Data as of: 09/01/2026
Terminal-Bench 2.0Overall Test details No documented difference in the test setupVersion: 2.0Metric: accuracyScoring: Higher is better	Winner73.202 %	57.303 %	Vals AI Source details Data as of: 06/04/2026
Terminal-Bench 2.1Overall Test details No documented difference in the test setupVersion: 2.1Metric: accuracyScoring: Higher is better	Winner76.404 %	53.558 %	Vals AI Source details Data as of: 09/03/2026
Vals IndexOverall Test details No documented difference in the test setupVersion: 2Metric: weighted index scoreScoring: Higher is better	Winner57.411 %	43.465 %	Vals AI Source details Data as of: 09/03/2026
Vals Multimodal IndexOverall Test details No documented difference in the test setupVersion: 1.2Metric: weighted index scoreScoring: Higher is better	Winner68.071 %	56.434 %	Vals AI Source details Data as of: 08/11/2026
Vibe Code Bench v1.1Overall Test details No documented difference in the test setupVersion: 1.1Metric: accuracyScoring: Higher is betterSettings: Harness: OpenHands	Winner69.847 %	37.891 %	Vals AI Source details Data as of: 09/03/2026
Code MigrationCLI Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value36.882 %	17.977 %	Vals AI Source details Data as of: 08/09/2026
CorpFin v2Exact Pages Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 48,000 tokens	Higher measured value65.618 %	64.802 %	Vals AI Source details Data as of: 08/06/2026
CyberBenchPatch Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner81.356 %	71.429 %	Vals AI Source details Data as of: 08/03/2026
EMBComps Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value64.681 %	61.395 %	Vals AI Source details Data as of: 08/06/2026
Finance Agent (v2)Adjustments Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value45.74 %	37.934 %	Vals AI Source details Data as of: 08/06/2026
GPQA DiamondFew-Shot CoT Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value93.434 %	89.899 %	Vals AI Source details Data as of: 08/09/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Criteria passed Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: criteria pass rateScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value82.246 %	63.768 %	Vals AI Source details Data as of: 08/07/2026
Legal Research BenchAdministrative / Regulatory · All-pass Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: all-pass rateScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value53.03 %	18.182 %	Vals AI Source details Data as of: 08/06/2026
LegalBenchConclusion Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value89.644 %	89.413 %	Vals AI Source details Data as of: 08/09/2026
LiveCodeBench v6Easy Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 256,000 tokens	98.447 %	Higher measured value99.068 %	Vals AI Source details Data as of: 08/09/2026
LMArena Text, Style ControlOverall Test details Test setup not documented as identicalNo direct winnerVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterGPT-5.5: Snapshot: gpt-5.5-high, Reasoning: high, Harness: Arena text, style control Kimi K2.6: Snapshot: kimi-k2.6, Harness: Arena text, style controlGPT-5.5: Style-controlled Arena rating from 63,265 anonymous pairwise votes.Kimi K2.6: Style-controlled Arena rating from 37,573 anonymous pairwise votes.	Higher measured value1,482.334 95% confidence interval: ±3.856The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	1,460.613 95% confidence interval: ±4.534The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	LMArena Source details Data as of: 09/01/2026
MMLU-ProBiology Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 96,000 tokens	Higher measured value94.003 %	93.724 %	Vals AI Source details Data as of: 08/09/2026
MortgageTaxNumerical Extraction Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value76.153 %	74.483 %	Vals AI Source details Data as of: 08/09/2026
ProgramBenchAlmost Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value9.5 %	0.5 %	Vals AI Source details Data as of: 08/09/2026
SAGEAutomata Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Temperature: 1, Output limit: 30,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 96,000 tokens	40.476 %	Higher measured value42.857 %	Vals AI Source details Data as of: 08/09/2026
SWE-bench Verified<15 min fix Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value91.753 %	87.629 %	Vals AI Source details Data as of: 08/08/2026
TaxEval v2Correctness Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value65.495 %	62.715 %	Vals AI Source details Data as of: 08/09/2026
Terminal-Bench 2.0Easy Test details Test setup not documented as identicalNo direct winnerVersion: 2.0Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: high, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 256,000 tokens	Higher measured value85 %	75 %	Vals AI Source details Data as of: 06/04/2026
Terminal-Bench 2.1Easy Test details Test setup not documented as identicalNo direct winnerVersion: 2.1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: high, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 256,000 tokens	No direct winner83.333 %	No direct winner83.333 %	Vals AI Source details Data as of: 08/06/2026
Vals IndexCorpFin v2 Test details Test setup not documented as identicalNo direct winnerVersion: 1.2Metric: benchmark scoreScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value69.58 %	68.182 %	Vals AI Source details Data as of: 08/09/2026
Vals Multimodal IndexCorpFin v2 Test details Test setup not documented as identicalNo direct winnerVersion: 1.2Metric: benchmark scoreScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value69.58 %	68.182 %	Vals AI Source details Data as of: 08/09/2026
Code MigrationCOBOL Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value70 %	57.143 %	Vals AI Source details Data as of: 08/09/2026
CorpFin v2Max Fitting Context Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 48,000 tokens	Higher measured value70.047 %	67.249 %	Vals AI Source details Data as of: 08/06/2026
CyberBenchPoC Test details No documented difference in the test setupVersion: 1Metric: accuracyScoring: Higher is better	Winner79.661 %	77.273 %	Vals AI Source details Data as of: 08/03/2026
EMBDataroom Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value81.227 %	75.069 %	Vals AI Source details Data as of: 08/06/2026
Finance Agent (v2)All-Pass Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value39.562 %	32.584 %	Vals AI Source details Data as of: 08/06/2026
GPQA DiamondZero-Shot CoT Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value92.929 %	88.384 %	Vals AI Source details Data as of: 08/09/2026
Harvey's Legal Agent BenchmarkAntitrust Competition · Task fully resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: task resolution rateScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	No direct winner0 %	No direct winner0 %	Vals AI Source details Data as of: 08/07/2026
Legal Research BenchAdministrative / Regulatory · Weighted partial credit Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: weighted partial-credit scoreScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value86.669 %	75.531 %	Vals AI Source details Data as of: 08/06/2026
LegalBenchInterpretation Tasks Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value83.836 %	82.197 %	Vals AI Source details Data as of: 08/09/2026
LiveCodeBench v6Hard Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 256,000 tokens	69.714 %	Higher measured value71.429 %	Vals AI Source details Data as of: 08/09/2026
LMArena Text, Style ControlBusiness, management and finance Test details No documented difference in the test setupVersion: style-control-v1Metric: style-controlled Bradley-Terry ratingScoring: Higher is betterGPT-5.5: Snapshot: gpt-5.5, Harness: Arena text, style control Kimi K2.6: Snapshot: kimi-k2.6, Harness: Arena text, style controlGPT-5.5: Style-controlled Arena rating from 12,904 anonymous pairwise votes.Kimi K2.6: Style-controlled Arena rating from 7,489 anonymous pairwise votes.	Winner1,485.915 95% confidence interval: ±6.577The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	1,455.777 95% confidence interval: ±7.725The Arena score measures human preference rather than a fixed capability test. The confidence interval and model configuration are part of the result.	LMArena Source details Data as of: 09/01/2026
MMLU-ProBusiness Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 96,000 tokens	Higher measured value92.015 %	91.635 %	Vals AI Source details Data as of: 08/09/2026
MortgageTaxSemantic Extraction Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value61.367 %	57.154 %	Vals AI Source details Data as of: 08/09/2026
ProgramBenchFully Resolved Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value0.5 %	0 %	Vals AI Source details Data as of: 08/09/2026
SAGECalculus Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Temperature: 1 Kimi K2.6: Top P: 0.95, Output limit: 96,000 tokens	Higher measured value72.222 %	22.839 %	Vals AI Source details Data as of: 08/09/2026
SWE-bench Verified>4 hours Test details Test setup not documented as identicalNo direct winnerVersion: 1Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	Higher measured value66.667 %	0 %	Vals AI Source details Data as of: 08/08/2026
TaxEval v2Stepwise Reasoning Test details Test setup not documented as identicalNo direct winnerVersion: 2Metric: accuracyScoring: Higher is betterGPT-5.5: Reasoning: xhigh, Output limit: 128,000 tokens Kimi K2.6: Top P: 0.95, Output limit: 128,000 tokens	84.464 %	Higher measured value86.59 %	Vals AI Source details Data as of: 08/09/2026
Key to the marks:better valuebetter, but not conclusivetie

How to read this comparison

Winning one benchmark is not an overall verdict

Your workload, budget, and required context length matter most. A coding benchmark says little about visual understanding or agent performance.

The standard price table uses direct developer rates. The provider comparison labels OpenRouter endpoints, regions, and special tariffs separately.

Every result links to its measurement source and retrieval date. Labels distinguish vendor reports, official benchmark leaderboards, and independent evaluations. Disputed or archived results are excluded.

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