Model comparison
Claude Sonnet 5 vs Longcat Flash Chat
Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 42.1 on the Noometry Index.
Last verified . 18 shared benchmarks.
Summary
- They share 18 benchmarks with published results for both. Claude Sonnet 5 scores higher in 8 categories and Longcat Flash Chat in 0 categories; 8 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where Claude Sonnet 5 leads 49.1 to 19.0.
- The biggest single-benchmark swing is NYT Connections (extended): 75.1% for Claude Sonnet 5 and 17.7% for Longcat Flash Chat.
- Longcat Flash Chat has downloadable open weights; the other is API-only.
Side by side
| Claude Sonnet 5 | Longcat Flash Chat | |
|---|---|---|
| Provider | Anthropic | Meituan |
| Noometry Index | 54.6 | 42.1 |
| Released | 2026-06-29 | — |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $2 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 51 | 19 |
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Category by category
Coding Claude Sonnet 5 leads
Claude Sonnet 5: 55.5 (#26), Longcat Flash Chat: 43.5 (#87)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Coding | 1483 | 1471 |
| DeepSWE | 53.8% | — |
| FrontierCode | 42.7% | — |
| CursorBench | 34.1% | — |
| LMArena WebDev | 1541 | — |
| SciCode | 54.3% | — |
| GSO | 37.3% | — |
| WeirdML | 68.8% | — |
| ALE-Bench | 1,463 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 5: 42.8 (#18), Longcat Flash Chat: —
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| APEX-Agents | 54.5% | — |
| GBAEval | 65.3% | — |
| LMArena Search | 1194 | — |
| Vending-Bench 2 | 6,378 | — |
Reasoning Claude Sonnet 5 leads
Claude Sonnet 5: 49.1 (#39), Longcat Flash Chat: 19.0 (#272)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| NYT Connections (extended) | 75.1% | 17.7% |
| LMArena Hard Prompts | 1461 | 1440 |
| SimpleBench | 60.6% | — |
| Kagi LLM Benchmark | — | 43.9% |
| CritPt | 16.9% | — |
| Chess Puzzles | 35% | — |
| Mystery Game Puzzles | 35% | — |
| DTBench | 92.5% | — |
| LMCA | 50% | — |
| Surface Evolver Bench | 60% | — |
| Bench to the Future 3 | 0.14 | — |
| Epoch Capabilities Index | 156.21 | — |
| ForecastBench | 61.1 | — |
Math Claude Sonnet 5 leads
Claude Sonnet 5: 66.2 (#27), Longcat Flash Chat: 39.4 (#107)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Math | 1467 | 1442 |
| FrontierMath (Tiers 1-3) | 65.6% | — |
| FrontierMath Tier 4 | 29.3% | — |
| OTIS Mock AIME 2024-2025 | 94.7% | — |
| ProofBench | 77% | — |
Knowledge Claude Sonnet 5 leads
Claude Sonnet 5: 55.6 (#47), Longcat Flash Chat: 40.6 (#116)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Expert | 1490 | 1454 |
| GPQA Diamond | 90.5% | — |
| SimpleQA Verified | 33.7% | — |
Multimodal Not comparable
Claude Sonnet 5: 42.4 (#31), Longcat Flash Chat: —
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Vision | 1274 | — |
| Blueprint-Bench 2 | 24.9% | — |
| LMArena Document | 1466 | — |
Multilingual Claude Sonnet 5 leads
Claude Sonnet 5: 53.8 (#55), Longcat Flash Chat: 51.9 (#101)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Non-English | 1431 | 1404 |
| LMArena Chinese | 1477 | 1465 |
| LMArena French | 1460 | 1456 |
| LMArena German | 1440 | 1408 |
| LMArena Japanese | 1422 | 1373 |
| LMArena Korean | 1411 | 1371 |
| LMArena Russian | 1451 | 1395 |
| LMArena Spanish | 1437 | 1445 |
Instruction Following Claude Sonnet 5 leads
Claude Sonnet 5: 76.3 (#41), Longcat Flash Chat: 74.4 (#96)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Instruction Following | 1452 | 1411 |
Long Context Claude Sonnet 5 leads
Claude Sonnet 5: 44.8 (#55), Longcat Flash Chat: 43.5 (#93)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Longer Query | 1463 | 1425 |
Writing & Preference Claude Sonnet 5 leads
Claude Sonnet 5: 69.2 (#25), Longcat Flash Chat: 61.0 (#91)
| Benchmark | Claude Sonnet 5 | Longcat Flash Chat |
|---|---|---|
| LMArena Text | 1442 | 1427 |
| LMArena Creative Writing | 1416 | 1388 |
| LMArena Multi-Turn | 1454 | 1418 |
| EQ-Bench Creative Writing | 1794 | — |
| EQ-Bench 4 | 1236 | — |
Frequently asked questions
Is Claude Sonnet 5 better than Longcat Flash Chat?
Claude Sonnet 5 is the stronger model overall, scoring 54.6 to 42.1 on the Noometry Index.
Is Claude Sonnet 5 or Longcat Flash Chat better for coding?
Claude Sonnet 5 scores higher on coding benchmarks: 55.5 versus 43.5 in the Noometry coding category.
How many benchmarks do Claude Sonnet 5 and Longcat Flash Chat share?
18 benchmarks have published results for both models. Claude Sonnet 5 has 51 scored results on Noometry and Longcat Flash Chat has 19.