Model comparison
Claude Sonnet 5.5 vs Longcat Flash Chat
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 41.5 on the Noometry Index.
Last verified . 0 shared benchmarks.
Summary
- The widest gap is in math, where Claude Sonnet 5.5 leads 88.7 to 36.6.
- Longcat Flash Chat has downloadable open weights; the other is API-only.
Side by side
| Claude Sonnet 5.5 | Longcat Flash Chat | |
|---|---|---|
| Provider | Anthropic | Meituan |
| Noometry Index | 60.5 | 41.5 |
| Released | 2026-09-28 | — |
| Weights | Proprietary | Open |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $2 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 16 | 19 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 65.5 (#6), Longcat Flash Chat: 42.9 (#85)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| FrontierCode | 52.1% | — |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1699 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| LMArena Coding | — | 1471 |
| ALE-Bench | 1,819 | — |
Agentic & Tool Use Not comparable
Claude Sonnet 5.5: 44.9 (#14), Longcat Flash Chat: —
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| APEX-Agents | 75.5% | — |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 52.4 (#29), Longcat Flash Chat: 18.3 (#267)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| Kagi LLM Benchmark | — | 43.9% |
| NYT Connections (extended) | — | 17.7% |
| CritPt | 31.4% | — |
| LMArena Hard Prompts | — | 1440 |
| Mystery Game Puzzles | 65% | — |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 88.7 (#4), Longcat Flash Chat: 36.6 (#107)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| OTIS Mock AIME 2024-2025 | 100% | — |
| ProofBench | 100% | — |
| LMArena Math | — | 1441 |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#11), Longcat Flash Chat: 40.0 (#111)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| GPQA Diamond | 95.6% | — |
| SimpleQA Verified | 46.5% | — |
| LMArena Expert | — | 1454 |
Multimodal Not comparable
Claude Sonnet 5.5: 53.2 (#5), Longcat Flash Chat: —
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| Furniture Assembly | 75% | — |
Multilingual Not comparable
Claude Sonnet 5.5: —, Longcat Flash Chat: 52.1 (#95)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Non-English | — | 1404 |
| LMArena Chinese | — | 1465 |
| LMArena French | — | 1457 |
| LMArena German | — | 1409 |
| LMArena Japanese | — | 1373 |
| LMArena Korean | — | 1372 |
| LMArena Russian | — | 1396 |
| LMArena Spanish | — | 1445 |
Instruction Following Not comparable
Claude Sonnet 5.5: —, Longcat Flash Chat: 74.6 (#92)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Instruction Following | — | 1411 |
Long Context Not comparable
Claude Sonnet 5.5: —, Longcat Flash Chat: 43.5 (#89)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Longer Query | — | 1425 |
Writing & Preference Not comparable
Claude Sonnet 5.5: —, Longcat Flash Chat: 61.2 (#88)
| Benchmark | Claude Sonnet 5.5 | Longcat Flash Chat |
|---|---|---|
| LMArena Text | — | 1427 |
| LMArena Creative Writing | — | 1388 |
| LMArena Multi-Turn | — | 1418 |
Frequently asked questions
Is Claude Sonnet 5.5 better than Longcat Flash Chat?
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 41.5 on the Noometry Index.
Is Claude Sonnet 5.5 or Longcat Flash Chat better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 65.5 versus 42.9 in the Noometry coding category.
How many benchmarks do Claude Sonnet 5.5 and Longcat Flash Chat share?
0 benchmarks have published results for both models. Claude Sonnet 5.5 has 16 scored results on Noometry and Longcat Flash Chat has 19.