Model comparison

GPT-5.1 vs Kimi K2.6

GPT-5.1 is the stronger model overall, scoring 49.0 to 47.7 on the Noometry Index. Kimi K2.6 costs 2.0× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Last verified . 37 shared benchmarks.

GPT-5.1 OpenAI

49.0

Rank #53 Confirmed

Kimi K2.6 Moonshot AI

47.7

Rank #60 Confirmed

Summary

  • They share 37 benchmarks with published results for both. GPT-5.1 scores higher in 4 categories and Kimi K2.6 in 6 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in multimodal, where GPT-5.1 leads 44.8 to 31.6.
  • The biggest single-benchmark swing is SimpleQA Verified: 48% for GPT-5.1 and 34.9% for Kimi K2.6.
  • Kimi K2.6 is cheaper at $0.95 / $4 per million input/output tokens, against $1.25 / $10 for GPT-5.1.
  • GPT-5.1 accepts more context: 400K tokens versus 262K.
  • Kimi K2.6 has downloadable open weights; the other is API-only.

Side by side

GPT-5.1 and Kimi K2.6 specifications
GPT-5.1Kimi K2.6
ProviderOpenAIMoonshot AI
Noometry Index49.047.7
Released2025-11-132026-04-20
WeightsProprietaryOpen
Context window400K262K
Max output128K262K
Input $ / M tokens$1.25$0.95
Output $ / M tokens$10$4
Results tracked6351

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Category by category

Coding Kimi K2.6 leads

GPT-5.1: 46.4 (#66), Kimi K2.6: 50.7 (#43)

Coding benchmarks
BenchmarkGPT-5.1Kimi K2.6
SWE-bench Verified68%76.7%
LMArena WebDev13951509
SciCode43.3%53.5%
WeirdML60.8%55.9%
LMArena Coding14541488
ALE-Bench1,1921,093
SWE-bench Verified (bash only)66%—
GSO13.7%—
LiveBench Coding72.5%—

Agentic & Tool Use GPT-5.1 leads

GPT-5.1: 32.7 (#60), Kimi K2.6: 21.9 (#137)

Agentic & Tool Use benchmarks
BenchmarkGPT-5.1Kimi K2.6
Vending-Bench 21,4736,205
Terminal-Bench47.6%—
OSWorld 2.0—4.6%
DeepResearch Bench42.8%—
ExploitBench—18.4%
GBAEval—0.9%
GDP.pdf—12%
LMArena Search1199—

Reasoning Too close to call

GPT-5.1: 39.8 (#58), Kimi K2.6: 40.5 (#55)

Reasoning benchmarks
BenchmarkGPT-5.1Kimi K2.6
CritPt4.9%8%
Chess Puzzles32%26%
LMArena Hard Prompts14571470
Mystery Game Puzzles19%18%
DTBench90.1%90.9%
LMCA43.9%37.3%
Epoch Capabilities Index149.64151.05
ARC-AGI-217.6%—
SimpleBench53.2%—
NYT Connections (extended)—87.2%
ARC-AGI-172.8%—
EnigmaEval11.2%—
EBR-Bench—2.4%
LiveBench Reasoning95.8%—
LiveBench Data Analysis72.1%—
ForecastBench58.1—
LiveBench78.8%—

Math Kimi K2.6 leads

GPT-5.1: 52.2 (#51), Kimi K2.6: 57.0 (#41)

Knowledge Kimi K2.6 leads

GPT-5.1: 50.6 (#71), Kimi K2.6: 54.0 (#54)

Knowledge benchmarks
BenchmarkGPT-5.1Kimi K2.6
GPQA Diamond87.6%90.8%
SimpleQA Verified48%34.9%
Vectara Hallucination Rate10.9%10.8%
LMArena Expert14701491
Humanity's Last Exam23.7%—
MMLU-Pro57.9%—
GPQA (HELM)44.2%—

Multimodal GPT-5.1 leads

GPT-5.1: 44.8 (#19), Kimi K2.6: 31.6 (#103)

Multimodal benchmarks
BenchmarkGPT-5.1Kimi K2.6
LMArena Vision12501283
LMArena Document14031451
VPCT58.7%—
Blueprint-Bench 2—3.9%
Furniture Assembly—21.7%

Multilingual Kimi K2.6 leads

GPT-5.1: 53.8 (#56), Kimi K2.6: 54.9 (#37)

Multilingual benchmarks
BenchmarkGPT-5.1Kimi K2.6
LMArena Non-English14311446
LMArena Chinese14951521
LMArena French14501471
LMArena German14381450
LMArena Japanese14531443
LMArena Korean14011427
LMArena Russian14351446
LMArena Spanish14331464

Instruction Following GPT-5.1 leads

GPT-5.1: 83.9 (#1), Kimi K2.6: 76.3 (#43)

Instruction Following benchmarks
BenchmarkGPT-5.1Kimi K2.6
LMArena Instruction Following14431451
LiveBench Instruction Following93.3%—
IFEval93.5%—

Long Context GPT-5.1 leads

GPT-5.1: 47.6 (#14), Kimi K2.6: 44.9 (#52)

Long Context benchmarks
BenchmarkGPT-5.1Kimi K2.6
LMArena Longer Query14471468
CL-bench23.7%—
CL-bench Life17.3%—

Writing & Preference Kimi K2.6 leads

GPT-5.1: 64.5 (#55), Kimi K2.6: 68.5 (#26)

Writing & Preference benchmarks
BenchmarkGPT-5.1Kimi K2.6
LMArena Text14431455
LMArena Creative Writing14271434
LMArena Multi-Turn14501453
EQ-Bench Creative Writing—1725
WildBench86.3%—
EQ-Bench 4—1202
LiveBench Language80.2%—

Frequently asked questions

Is GPT-5.1 better than Kimi K2.6?

GPT-5.1 is the stronger model overall, scoring 49.0 to 47.7 on the Noometry Index. Kimi K2.6 costs 2.0× less per token, which makes it the better buy when GPT-5.1's lead doesn't matter for your workload.

Which is cheaper, GPT-5.1 or Kimi K2.6?

Kimi K2.6 is cheaper. It lists at $0.95 per million input tokens and $4 per million output tokens; GPT-5.1 lists at $1.25 and $10.

Is GPT-5.1 or Kimi K2.6 better for coding?

Kimi K2.6 scores higher on coding benchmarks: 50.7 versus 46.4 in the Noometry coding category.

Which has the bigger context window?

GPT-5.1 does, with 400K tokens against 262K.

How many benchmarks do GPT-5.1 and Kimi K2.6 share?

37 benchmarks have published results for both models. GPT-5.1 has 63 scored results on Noometry and Kimi K2.6 has 51.

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