Model comparison

GPT-5.6 Sol vs Kimi K2.5 Instant

GPT-5.6 Sol is the stronger model overall, scoring 65.0 to 43.6 on the Noometry Index.

Last verified . 18 shared benchmarks.

GPT-5.6 Sol OpenAI

65.0

Rank #7 Confirmed

Kimi K2.5 Instant Moonshot AI

43.6

Rank #89 Confirmed

Summary

  • They share 18 benchmarks with published results for both. GPT-5.6 Sol scores higher in 9 categories and Kimi K2.5 Instant in 0 categories; 9 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Sol leads 85.6 to 39.4.
  • Kimi K2.5 Instant has downloadable open weights; the other is API-only.

Side by side

GPT-5.6 Sol and Kimi K2.5 Instant specifications
GPT-5.6 SolKimi K2.5 Instant
ProviderOpenAIMoonshot AI
Noometry Index65.043.6
Released2026-07-09—
WeightsProprietaryOpen
Context window1.05M—
Max output128K—
Input $ / M tokens$4—
Output $ / M tokens$20—
Results tracked6518

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Category by category

Coding GPT-5.6 Sol leads

GPT-5.6 Sol: 65.1 (#7), Kimi K2.5 Instant: 42.6 (#97)

Coding benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena WebDev16181404
LMArena Coding14981484
DeepSWE72.7%—
FrontierCode47.5%—
CursorBench41.7%—
FrontierSWE32.2%—
SciCode57.1%—
GSO76.5%—
WeirdML89.4%—
MirrorCode20%—
ALE-Bench2,177—

Agentic & Tool Use Not comparable

GPT-5.6 Sol: 50.3 (#7), Kimi K2.5 Instant: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
APEX-Agents51.4%—
OSWorld 2.027.3%—
τ²-bench Banking46.9%—
PostTrainBench36.2%—
BALROG60%—
GBAEval52.6%—
GDP.pdf30.7%—
LMArena Search1257—
Vending-Bench 29,619—

Reasoning GPT-5.6 Sol leads

GPT-5.6 Sol: 74.8 (#8), Kimi K2.5 Instant: 29.7 (#90)

Reasoning benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Hard Prompts14841443
ARC-AGI-292.5%—
SimpleBench71.7%—
Kagi LLM Benchmark67%—
NYT Connections (extended)93.8%—
ARC-AGI-197.5%—
CritPt32.3%—
Chess Puzzles64%—
EnigmaEval37.1%—
EBR-Bench44.8%—
Mystery Game Puzzles58%—
DTBench96%—
LMCA59.2%—
Surface Evolver Bench93.1%—
Bench to the Future 30.14—
Epoch Capabilities Index161.66—

Math GPT-5.6 Sol leads

GPT-5.6 Sol: 85.6 (#9), Kimi K2.5 Instant: 39.4 (#105)

Math benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Math14741442
FrontierMath (Tiers 1-3)89.1%—
FrontierMath Tier 482.9%—
OTIS Mock AIME 2024-2025100%—
ProofBench83%—
FrontierMath Erdős0%—

Knowledge GPT-5.6 Sol leads

GPT-5.6 Sol: 64.3 (#18), Kimi K2.5 Instant: 40.2 (#123)

Knowledge benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Expert15161440
GPQA Diamond93.5%—
SimpleQA Verified69.7%—
Vectara Hallucination Rate12.4%—

Multimodal GPT-5.6 Sol leads

GPT-5.6 Sol: 48.6 (#9), Kimi K2.5 Instant: 40.2 (#50)

Multimodal benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Vision12811254
Blueprint-Bench 233.6%—
Furniture Assembly56.7%—
LMArena Document1483—

Multilingual GPT-5.6 Sol leads

GPT-5.6 Sol: 55.3 (#32), Kimi K2.5 Instant: 52.0 (#94)

Multilingual benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Non-English14521406
LMArena Chinese15271449
LMArena French14771403
LMArena German14761413
LMArena Korean14421378
LMArena Russian14681404
LMArena Spanish14411447
LMArena Japanese1471—

Instruction Following GPT-5.6 Sol leads

GPT-5.6 Sol: 77.7 (#16), Kimi K2.5 Instant: 75.3 (#65)

Instruction Following benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Instruction Following14821430

Long Context GPT-5.6 Sol leads

GPT-5.6 Sol: 45.4 (#42), Kimi K2.5 Instant: 43.9 (#83)

Long Context benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Longer Query14801435

Writing & Preference GPT-5.6 Sol leads

GPT-5.6 Sol: 73.3 (#12), Kimi K2.5 Instant: 60.6 (#95)

Writing & Preference benchmarks
BenchmarkGPT-5.6 SolKimi K2.5 Instant
LMArena Text14571420
LMArena Creative Writing14481381
LMArena Multi-Turn14601427
EQ-Bench Creative Writing1972—
EQ-Bench 41250—

Frequently asked questions

Is GPT-5.6 Sol better than Kimi K2.5 Instant?

GPT-5.6 Sol is the stronger model overall, scoring 65.0 to 43.6 on the Noometry Index.

Is GPT-5.6 Sol or Kimi K2.5 Instant better for coding?

GPT-5.6 Sol scores higher on coding benchmarks: 65.1 versus 42.6 in the Noometry coding category.

How many benchmarks do GPT-5.6 Sol and Kimi K2.5 Instant share?

18 benchmarks have published results for both models. GPT-5.6 Sol has 65 scored results on Noometry and Kimi K2.5 Instant has 18.

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