Model comparison
GPT-5 Nano vs Longcat Flash Chat
Longcat Flash Chat is the stronger model overall, scoring 42.1 to 33.5 on the Noometry Index.
Last verified . 17 shared benchmarks.
Summary
- They share 17 benchmarks with published results for both. GPT-5 Nano scores higher in 1 category and Longcat Flash Chat in 7 categories; 7 gaps are clear of the uncertainty.
- The widest gap is in writing & preference, where Longcat Flash Chat leads 61.0 to 39.1.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 62.2% for GPT-5 Nano and 43.9% for Longcat Flash Chat.
- Longcat Flash Chat has downloadable open weights; the other is API-only.
Side by side
| GPT-5 Nano | Longcat Flash Chat | |
|---|---|---|
| Provider | OpenAI | Meituan |
| Noometry Index | 33.5 | 42.1 |
| Released | 2025-08-07 | — |
| Weights | Proprietary | Open |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $0.05 | — |
| Output $ / M tokens | $0.40 | — |
| Results tracked | 49 | 19 |
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Category by category
Coding Longcat Flash Chat leads
GPT-5 Nano: 33.6 (#254), Longcat Flash Chat: 43.5 (#87)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Coding | 1351 | 1471 |
| SWE-bench Verified (bash only) | 34.8% | — |
| WeirdML | 38.1% | — |
| ALE-Bench | 718.67 | — |
Agentic & Tool Use Not comparable
GPT-5 Nano: 25.8 (#106), Longcat Flash Chat: —
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| Terminal-Bench | 21.8% | — |
| Berkeley Function Calling Leaderboard | 51.5% | — |
Reasoning Longcat Flash Chat leads
GPT-5 Nano: 16.3 (#306), Longcat Flash Chat: 19.0 (#272)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| Kagi LLM Benchmark | 62.2% | 43.9% |
| LMArena Hard Prompts | 1328 | 1440 |
| ARC-AGI-2 | 2.6% | — |
| NYT Connections (extended) | — | 17.7% |
| ARC-AGI-1 | 20.7% | — |
| Chess Puzzles | 27% | — |
| Mystery Game Puzzles | 9% | — |
| DTBench | 62.7% | — |
| LMCA | 7.9% | — |
| Epoch Capabilities Index | 139.38 | — |
| ForecastBench | 59.1 | — |
Math Longcat Flash Chat leads
GPT-5 Nano: 29.4 (#241), Longcat Flash Chat: 39.4 (#107)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Math | 1317 | 1442 |
| FrontierMath (Tiers 1-3) | 20% | — |
| FrontierMath Tier 4 | 2.4% | — |
| OTIS Mock AIME 2024-2025 | 81.1% | — |
| ProofBench | 12% | — |
| Omni-MATH | 54.6% | — |
| MATH Level 5 | 95.2% | — |
| FrontierMath (Feb 2025 set) | 8.3% | — |
| FrontierMath Tier 4 (v1) | 2.1% | — |
Knowledge Longcat Flash Chat leads
GPT-5 Nano: 35.9 (#178), Longcat Flash Chat: 40.6 (#116)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Expert | 1321 | 1454 |
| GPQA Diamond | 69.4% | — |
| SimpleQA Verified | 11.7% | — |
| MMLU-Pro | 77.8% | — |
| Vectara Hallucination Rate | 10.5% | — |
| GPQA (HELM) | 67.9% | — |
Multimodal Not comparable
GPT-5 Nano: 31.3 (#108), Longcat Flash Chat: —
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Vision | 1159 | — |
| VPCT | 37.2% | — |
Multilingual Longcat Flash Chat leads
GPT-5 Nano: 45.3 (#172), Longcat Flash Chat: 51.9 (#101)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Non-English | 1313 | 1404 |
| LMArena Chinese | 1356 | 1465 |
| LMArena German | 1327 | 1408 |
| LMArena Japanese | 1226 | 1373 |
| LMArena Korean | 1269 | 1371 |
| LMArena Russian | 1296 | 1395 |
| LMArena Spanish | 1360 | 1445 |
| LMArena French | — | 1456 |
Instruction Following Too close to call
GPT-5 Nano: 75.0 (#79), Longcat Flash Chat: 74.4 (#96)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Instruction Following | 1306 | 1411 |
| IFEval | 93.2% | — |
Long Context Longcat Flash Chat leads
GPT-5 Nano: 31.3 (#281), Longcat Flash Chat: 43.5 (#93)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Longer Query | 1312 | 1425 |
| Fiction.LiveBench | 44.4% | — |
Writing & Preference Longcat Flash Chat leads
GPT-5 Nano: 39.1 (#249), Longcat Flash Chat: 61.0 (#91)
| Benchmark | GPT-5 Nano | Longcat Flash Chat |
|---|---|---|
| LMArena Text | 1320 | 1427 |
| LMArena Creative Writing | 1249 | 1388 |
| LMArena Multi-Turn | 1311 | 1418 |
| EQ-Bench Creative Writing | 705 | — |
| WildBench | 80.6% | — |
Frequently asked questions
Is GPT-5 Nano better than Longcat Flash Chat?
Longcat Flash Chat is the stronger model overall, scoring 42.1 to 33.5 on the Noometry Index.
Is GPT-5 Nano or Longcat Flash Chat better for coding?
Longcat Flash Chat scores higher on coding benchmarks: 43.5 versus 33.6 in the Noometry coding category.
How many benchmarks do GPT-5 Nano and Longcat Flash Chat share?
17 benchmarks have published results for both models. GPT-5 Nano has 49 scored results on Noometry and Longcat Flash Chat has 19.