# 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.

- Canonical page: https://noometry.com/compare/gpt-5-5-pro-vs-longcat-flash-chat
- Last updated: 2026-10-10
- Shared benchmarks: 0

## 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.

## Snapshot

| | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| Provider | OpenAI | Meituan |
| Noometry Index | 64.3 | 42.1 |
| Rank | 8 | 120 |
| Context | 1.05M | — |
| Input $/M | $30 | — |
| Output $/M | $180 | — |
| Weights | Proprietary | Open |

## Coding

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| LMArena Coding | — | 1471 |

## Reasoning

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| ARC-AGI-2 | 84.6% | — |
| SimpleBench | 76.9% | — |
| Kagi LLM Benchmark | — | 43.9% |
| NYT Connections (extended) | — | 17.7% |
| ARC-AGI-1 | 96.5% | — |
| CritPt | 30.6% | — |
| Chess Puzzles | 64% | — |
| LMArena Hard Prompts | — | 1440 |
| DTBench | 96% | — |
| LMCA | 53.9% | — |
| Epoch Capabilities Index | 162.07 | — |

## Math

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| FrontierMath (Tiers 1-3) | 87.7% | — |
| FrontierMath Tier 4 | 78% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| LMArena Math | — | 1442 |
| FrontierMath (Feb 2025 set) | 52.4% | — |
| FrontierMath Tier 4 (v1) | 39.6% | — |

## Knowledge

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| GPQA Diamond | 93.9% | — |
| LMArena Expert | — | 1454 |

## Multilingual

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

| Benchmark | GPT-5.5 Pro | Longcat 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

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| LMArena Instruction Following | — | 1411 |

## Long Context

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| LMArena Longer Query | — | 1425 |

## Writing & Preference

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

| Benchmark | GPT-5.5 Pro | Longcat Flash Chat |
|---|---|---|
| LMArena Text | — | 1427 |
| LMArena Creative Writing | — | 1388 |
| LMArena Multi-Turn | — | 1418 |

## FAQ

### 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.