Model comparison
Claude Opus 4.5 vs Longcat Flash Chat
Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 42.1 on the Noometry Index.
Last verified . 19 shared benchmarks.
Summary
- They share 19 benchmarks with published results for both. Claude Opus 4.5 scores higher in 7 categories and Longcat Flash Chat in 1 category; 7 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Opus 4.5 leads 42.6 to 19.0.
- The biggest single-benchmark swing is Kagi LLM Benchmark: 80.2% for Claude Opus 4.5 and 43.9% for Longcat Flash Chat.
- Longcat Flash Chat has downloadable open weights; the other is API-only.
Side by side
| Claude Opus 4.5 | Longcat Flash Chat | |
|---|---|---|
| Provider | Anthropic | Meituan |
| Noometry Index | 50.5 | 42.1 |
| Released | 2025-11-01 | — |
| Weights | Proprietary | Open |
| Context window | 200K | — |
| Max output | 64K | — |
| Input $ / M tokens | $5 | — |
| Output $ / M tokens | $25 | — |
| Results tracked | 69 | 19 |
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Category by category
Coding Claude Opus 4.5 leads
Claude Opus 4.5: 54.8 (#27), Longcat Flash Chat: 43.5 (#87)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Coding | 1504 | 1471 |
| SWE-bench Verified | 76.7% | — |
| SWE-bench Verified (bash only) | 76.8% | — |
| LMArena WebDev | 1494 | — |
| SWE-bench Multilingual | 70.7% | — |
| GSO | 26.5% | — |
| WeirdML | 63.7% | — |
| ALE-Bench | 1,025 | — |
| AlgoTune | 1.77 | — |
Agentic & Tool Use Not comparable
Claude Opus 4.5: 47.3 (#12), Longcat Flash Chat: —
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| Terminal-Bench | 63.1% | — |
| Berkeley Function Calling Leaderboard | 77.5% | — |
| GDPval | 45.5% | — |
| Remote Labor Index | 3.8% | — |
| τ²-bench Airline | 84% | — |
| τ²-bench Banking | 24.7% | — |
| τ²-bench Retail | 79.6% | — |
| τ²-bench Telecom | 92.3% | — |
| Cybench | 82% | — |
| DeepResearch Bench | 54.8% | — |
| OSWorld | 66.3% | — |
| BALROG | 43.5% | — |
| LMArena Search | 1180 | — |
| METR Time Horizons | 75% | — |
| Vending-Bench 2 | 4,967 | — |
Reasoning Claude Opus 4.5 leads
Claude Opus 4.5: 42.6 (#51), Longcat Flash Chat: 19.0 (#272)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| Kagi LLM Benchmark | 80.2% | 43.9% |
| NYT Connections (extended) | 52.5% | 17.7% |
| LMArena Hard Prompts | 1476 | 1440 |
| ARC-AGI-2 | 37.6% | — |
| SimpleBench | 62% | — |
| ARC-AGI-1 | 80% | — |
| Chess Puzzles | 12% | — |
| EnigmaEval | 11.9% | — |
| EBR-Bench | 14.3% | — |
| Mystery Game Puzzles | 22% | — |
| DTBench | 89.9% | — |
| LMCA | 44.5% | — |
| Epoch Capabilities Index | 150.09 | — |
| ForecastBench | 60.7 | — |
Math Too close to call
Claude Opus 4.5: 38.6 (#132), Longcat Flash Chat: 39.4 (#107)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Math | 1463 | 1442 |
| FrontierMath (Tiers 1-3) | 34.4% | — |
| FrontierMath Tier 4 | 4.9% | — |
| OTIS Mock AIME 2024-2025 | 86.1% | — |
| ProofBench | 36% | — |
| FrontierMath (Feb 2025 set) | 20.7% | — |
| FrontierMath Tier 4 (v1) | 4.2% | — |
Knowledge Claude Opus 4.5 leads
Claude Opus 4.5: 56.5 (#44), Longcat Flash Chat: 40.6 (#116)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Expert | 1487 | 1454 |
| GPQA Diamond | 86% | — |
| Humanity's Last Exam | 25.2% | — |
| SimpleQA Verified | 45.7% | — |
| Vectara Hallucination Rate | 10.9% | — |
Multimodal Not comparable
Claude Opus 4.5: 31.4 (#107), Longcat Flash Chat: —
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| GeoBench | 75% | — |
| VPCT | 40% | — |
| Furniture Assembly | 28.3% | — |
| LMArena Document | 1462 | — |
Multilingual Claude Opus 4.5 leads
Claude Opus 4.5: 54.3 (#47), Longcat Flash Chat: 51.9 (#101)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Non-English | 1438 | 1404 |
| LMArena Chinese | 1470 | 1465 |
| LMArena French | 1471 | 1456 |
| LMArena German | 1449 | 1408 |
| LMArena Japanese | 1416 | 1373 |
| LMArena Korean | 1424 | 1371 |
| LMArena Russian | 1447 | 1395 |
| LMArena Spanish | 1458 | 1445 |
Instruction Following Claude Opus 4.5 leads
Claude Opus 4.5: 77.5 (#19), Longcat Flash Chat: 74.4 (#96)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Instruction Following | 1478 | 1411 |
Long Context Claude Opus 4.5 leads
Claude Opus 4.5: 46.5 (#22), Longcat Flash Chat: 43.5 (#93)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Longer Query | 1480 | 1425 |
| CL-bench | 21.1% | — |
Writing & Preference Claude Opus 4.5 leads
Claude Opus 4.5: 68.1 (#28), Longcat Flash Chat: 61.0 (#91)
| Benchmark | Claude Opus 4.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Text | 1451 | 1427 |
| LMArena Creative Writing | 1445 | 1388 |
| LMArena Multi-Turn | 1466 | 1418 |
| EQ-Bench Creative Writing | 1687 | — |
Frequently asked questions
Is Claude Opus 4.5 better than Longcat Flash Chat?
Claude Opus 4.5 is the stronger model overall, scoring 50.5 to 42.1 on the Noometry Index.
Is Claude Opus 4.5 or Longcat Flash Chat better for coding?
Claude Opus 4.5 scores higher on coding benchmarks: 54.8 versus 43.5 in the Noometry coding category.
How many benchmarks do Claude Opus 4.5 and Longcat Flash Chat share?
19 benchmarks have published results for both models. Claude Opus 4.5 has 69 scored results on Noometry and Longcat Flash Chat has 19.