Model comparison

GPT-5.5 Pro vs Longcat Flash Chat

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 42.1 on the Noometry Index.

Last verified . 0 shared benchmarks.

GPT-5.5 Pro OpenAI

64.3

Rank #8 Confirmed

Longcat Flash Chat Meituan

42.1

Rank #120 Confirmed

Summary

  • The widest gap is in reasoning, where GPT-5.5 Pro leads 73.3 to 19.0.
  • Longcat Flash Chat has downloadable open weights; the other is API-only.

Side by side

GPT-5.5 Pro and Longcat Flash Chat specifications
GPT-5.5 ProLongcat Flash Chat
ProviderOpenAIMeituan
Noometry Index64.342.1
Released2026-04-23—
WeightsProprietaryOpen
Context window1.05M—
Max output128K—
Input $ / M tokens$30—
Output $ / M tokens$180—
Results tracked1419

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Category by category

Coding Not comparable

GPT-5.5 Pro: —, Longcat Flash Chat: 43.5 (#87)

Coding benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
LMArena Coding—1471

Reasoning GPT-5.5 Pro leads

GPT-5.5 Pro: 73.3 (#10), Longcat Flash Chat: 19.0 (#272)

Reasoning benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
ARC-AGI-284.6%—
SimpleBench76.9%—
Kagi LLM Benchmark—43.9%
NYT Connections (extended)—17.7%
ARC-AGI-196.5%—
CritPt30.6%—
Chess Puzzles64%—
LMArena Hard Prompts—1440
DTBench96%—
LMCA53.9%—
Epoch Capabilities Index162.07—

Math GPT-5.5 Pro leads

GPT-5.5 Pro: 84.0 (#10), Longcat Flash Chat: 39.4 (#107)

Math benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
FrontierMath (Tiers 1-3)87.7%—
FrontierMath Tier 478%—
OTIS Mock AIME 2024-2025100%—
LMArena Math—1442
FrontierMath (Feb 2025 set)52.4%—
FrontierMath Tier 4 (v1)39.6%—

Knowledge GPT-5.5 Pro leads

GPT-5.5 Pro: 64.1 (#19), Longcat Flash Chat: 40.6 (#116)

Knowledge benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
GPQA Diamond93.9%—
LMArena Expert—1454

Multilingual Not comparable

GPT-5.5 Pro: —, Longcat Flash Chat: 51.9 (#101)

Multilingual benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
LMArena Non-English—1404
LMArena Chinese—1465
LMArena French—1456
LMArena German—1408
LMArena Japanese—1373
LMArena Korean—1371
LMArena Russian—1395
LMArena Spanish—1445

Instruction Following Not comparable

GPT-5.5 Pro: —, Longcat Flash Chat: 74.4 (#96)

Instruction Following benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
LMArena Instruction Following—1411

Long Context Not comparable

GPT-5.5 Pro: —, Longcat Flash Chat: 43.5 (#93)

Long Context benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
LMArena Longer Query—1425

Writing & Preference Not comparable

GPT-5.5 Pro: —, Longcat Flash Chat: 61.0 (#91)

Writing & Preference benchmarks
BenchmarkGPT-5.5 ProLongcat Flash Chat
LMArena Text—1427
LMArena Creative Writing—1388
LMArena Multi-Turn—1418

Frequently asked questions

Is GPT-5.5 Pro better than Longcat Flash Chat?

GPT-5.5 Pro is the stronger model overall, scoring 64.3 to 42.1 on the Noometry Index.

How many benchmarks do GPT-5.5 Pro and Longcat Flash Chat share?

0 benchmarks have published results for both models. GPT-5.5 Pro has 14 scored results on Noometry and Longcat Flash Chat has 19.

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