Model comparison

GPT-5.6 Luna vs Longcat Flash Chat

GPT-5.6 Luna is the stronger model overall, scoring 54.6 to 42.1 on the Noometry Index.

Last verified . 19 shared benchmarks.

GPT-5.6 Luna OpenAI

54.6

Rank #30 Confirmed

Longcat Flash Chat Meituan

42.1

Rank #120 Confirmed

Summary

  • They share 19 benchmarks with published results for both. GPT-5.6 Luna scores higher in 8 categories and Longcat Flash Chat in 0 categories; 6 gaps are clear of the uncertainty.
  • The widest gap is in math, where GPT-5.6 Luna leads 77.7 to 39.4.
  • The biggest single-benchmark swing is NYT Connections (extended): 69.4% for GPT-5.6 Luna and 17.7% for Longcat Flash Chat.
  • Longcat Flash Chat has downloadable open weights; the other is API-only.

Side by side

GPT-5.6 Luna and Longcat Flash Chat specifications
GPT-5.6 LunaLongcat Flash Chat
ProviderOpenAIMeituan
Noometry Index54.642.1
Released2026-07-09—
WeightsProprietaryOpen
Context window1.05M—
Max output128K—
Input $ / M tokens$0.20—
Output $ / M tokens$1.20—
Results tracked5219

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Category by category

Coding GPT-5.6 Luna leads

GPT-5.6 Luna: 54.5 (#28), Longcat Flash Chat: 43.5 (#87)

Coding benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Coding14661471
DeepSWE67.2%—
FrontierCode39.8%—
CursorBench35.9%—
LMArena WebDev1519—
SciCode53.6%—
WeirdML60.9%—
ALE-Bench1,667—

Agentic & Tool Use Not comparable

GPT-5.6 Luna: 34.4 (#45), Longcat Flash Chat: —

Agentic & Tool Use benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
APEX-Agents43%—
BALROG45.6%—
GDP.pdf22.7%—
Vending-Bench 24,095—

Reasoning GPT-5.6 Luna leads

GPT-5.6 Luna: 47.6 (#43), Longcat Flash Chat: 19.0 (#272)

Reasoning benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
Kagi LLM Benchmark49.1%43.9%
NYT Connections (extended)69.4%17.7%
LMArena Hard Prompts14511440
ARC-AGI-259.5%—
SimpleBench46.8%—
ARC-AGI-188%—
CritPt20.6%—
Chess Puzzles40%—
Mystery Game Puzzles21%—
DTBench89.1%—
LMCA48.5%—
Surface Evolver Bench61.9%—
Epoch Capabilities Index156.39—

Math GPT-5.6 Luna leads

GPT-5.6 Luna: 77.7 (#14), Longcat Flash Chat: 39.4 (#107)

Math benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Math14581442
FrontierMath (Tiers 1-3)82.1%—
FrontierMath Tier 461%—
OTIS Mock AIME 2024-202598.3%—
ProofBench60%—

Knowledge GPT-5.6 Luna leads

GPT-5.6 Luna: 58.5 (#34), Longcat Flash Chat: 40.6 (#116)

Knowledge benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Expert14781454
GPQA Diamond91.6%—
SimpleQA Verified41%—

Multimodal Not comparable

GPT-5.6 Luna: 42.7 (#28), Longcat Flash Chat: —

Multimodal benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Vision1258—
Blueprint-Bench 222.6%—
Furniture Assembly42.5%—
LMArena Document1457—

Multilingual Too close to call

GPT-5.6 Luna: 52.8 (#78), Longcat Flash Chat: 51.9 (#101)

Multilingual benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Non-English14171404
LMArena Chinese14701465
LMArena French14561456
LMArena German14541408
LMArena Japanese14111373
LMArena Korean14151371
LMArena Russian14281395
LMArena Spanish14481445

Instruction Following GPT-5.6 Luna leads

GPT-5.6 Luna: 75.6 (#57), Longcat Flash Chat: 74.4 (#96)

Instruction Following benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Instruction Following14371411

Long Context Too close to call

GPT-5.6 Luna: 43.9 (#82), Longcat Flash Chat: 43.5 (#93)

Long Context benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Longer Query14361425

Writing & Preference GPT-5.6 Luna leads

GPT-5.6 Luna: 68.0 (#29), Longcat Flash Chat: 61.0 (#91)

Writing & Preference benchmarks
BenchmarkGPT-5.6 LunaLongcat Flash Chat
LMArena Text14311427
LMArena Creative Writing13961388
LMArena Multi-Turn14341418
EQ-Bench Creative Writing1829—
EQ-Bench 41156—

Frequently asked questions

Is GPT-5.6 Luna better than Longcat Flash Chat?

GPT-5.6 Luna is the stronger model overall, scoring 54.6 to 42.1 on the Noometry Index.

Is GPT-5.6 Luna or Longcat Flash Chat better for coding?

GPT-5.6 Luna scores higher on coding benchmarks: 54.5 versus 43.5 in the Noometry coding category.

How many benchmarks do GPT-5.6 Luna and Longcat Flash Chat share?

19 benchmarks have published results for both models. GPT-5.6 Luna has 52 scored results on Noometry and Longcat Flash Chat has 19.

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