Claude Sonnet 5.5 vs Gemini 3.5 Flash
Claude Sonnet 5.5 
Gemini 3.5 Flash Verdict
- Claude Sonnet 5.5 (max) leads on quality: 67.6 vs 63.0.
- Claude Sonnet 5.5 (max) is stronger in agents & tools, coding, composite, long context, maths, reasoning.
- Gemini 3.5 Flash (medium) is stronger in knowledge, human preference, instruction following, multimodal.
- Gemini 3.5 Flash (medium) is 1.2× cheaper ($3.38 vs $4.00 per 1M blended).
- Gemini 3.5 Flash (medium) streams 1.5× faster (206 vs 141 tokens per second).
| Metric | Claude Sonnet 5.5 (max) | Gemini 3.5 Flash (medium) |
|---|---|---|
| BenchLeader Index | 67.6 | 63.0 |
| Agents & tools score | 69.5 | 67.9 |
| Coding score | 69.8 | 56.8 |
| Composite score | 72.6 | 67.6 |
| Knowledge score | 65.4 | 71.1 |
| Long context score | 66.6 | 62.3 |
| Maths score | 72.9 | 66.8 |
| Reasoning score | 81.1 | 61.7 |
| Human preference score | – | 67.1 |
| Instruction following score | – | 72.7 |
| Multimodal score | – | 66.5 |
| Blended price $/M | $4.00 | $3.38 |
| Output speed | 141 tok/s | 206 tok/s |
| Time to first answer | 487.1 s | 13.6 s |
| Context window | 1M | 1.0M |
| GPQA Diamond | 95.6% | – |
| FrontierMath Tiers 1–3 | 88.8% | – |
| FrontierMath Tier 4 | 80.5% | – |
| OTIS Mock AIME | 100.0% | – |
| SimpleQA Verified | 46.5% | – |
| Terminal-Bench | 61.8% | – |
| SciCode | 61.0% | – |
| APEX-Agents | 75.5% | – |
| ProofBench | 100.0% | – |
| LMArena Text | – | 1476 |
| LMArena Hard Prompts | – | 1495 |
| LMArena Coding | – | 1506 |
| LMArena WebDev | – | 1491 |
| LMArena Vision | – | 1309 |
| LMArena Agent | 12 | – |
| LiveBench | 75.7% | – |
| LiveBench Reasoning | 91.6% | – |
| LiveBench Coding | 91.4% | – |
| LiveBench Agentic Coding | 56.3% | – |
| LiveBench Mathematics | 96.1% | – |
| LiveBench Data Analysis | 59.5% | – |
| LiveBench Language | 78.0% | – |
| LiveBench Instruction Following | 56.8% | – |
| AA Intelligence Index v4.3.2 | 56 | 33.6 |
| IFBench | – | 74.6% |
| AA-LCR | 82.7% | 74.3% |
| MMMU-Pro | – | 83.9% |
| AA-Omniscience | 32.3 | 20.8 |
| Terminal-Bench Hard | – | 39.4% |
| GPQA Diamond (AA) | – | 92.1% |
| Humanity's Last Exam (AA) | 55.0% | 41.3% |
| SciCode (AA) | 61.0% | – |
| τ²-Bench Telecom (AA) | – | 95.6% |
| CritPt | 31.4% | 10.9% |
| GDPval-AA v2.1 | 67.0% | – |
| Analyst Agent (AA) | 57.5% | – |
| LMArena Maths | – | 1482 |
| LMArena Creative Writing | – | 1469 |
| LMArena Instruction Following | – | 1466 |
| LMArena Multi-turn | – | 1478 |
| LMArena Longer Queries | – | 1480 |
| LMArena Document | – | 1461 |
| Mystery Game Puzzles | 65.0% | – |
| Surface Evolver Bench | – | 58.1% |
| DeepSWE v1.1 | – | 37.4% |
| CursorBench | 55.5% | – |
| GDP.pdf | – | 14.0% |
| FrontierSWE | 61.9% | – |
| Terminal-Bench 4.0 (AA) | 63.6% | – |
| AutomationBench | 71.8% | – |
| GDP.pdf | 25.8% | – |
| MLCR | 75.0% | – |
| Harvey LAB | 2.8% | – |
| AA-Omniscience: accuracy | 54.0% | 51.0% |
| AA-Omniscience: non-hallucination | 53.0% | 38.2% |
| AA-Briefcase v1.1 | 1823 | – |
Data as of 2026-10-11. Best configuration of each model; every score links to its source on the model pages.
Claude Sonnet 5.5 vs Gemini 3.5 Flash: questions
- Is Claude Sonnet 5.5 better than Gemini 3.5 Flash?
- Claude Sonnet 5.5 (max) leads on quality: 67.6 vs 63.0. The BenchLeader Index combines every independent quality benchmark; Claude Sonnet 5.5 (max) is ahead overall as of 2026-10-11, but check the category scores for your use.
- Is Claude Sonnet 5.5 better than Gemini 3.5 Flash for coding?
- Claude Sonnet 5.5 scores higher in coding (70 vs 57 on the category index, where 50 is average).
- Is Claude Sonnet 5.5 better than Gemini 3.5 Flash for agentic tasks?
- Claude Sonnet 5.5 scores higher in agentic tasks (70 vs 68 on the category index, where 50 is average).
- Which is cheaper, Claude Sonnet 5.5 or Gemini 3.5 Flash?
- Gemini 3.5 Flash is cheaper: $3.38 against $4.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Claude Sonnet 5.5 or Gemini 3.5 Flash?
- Gemini 3.5 Flash streams faster: 206 against 141 output tokens per second.
- Which has the larger context window?
- Gemini 3.5 Flash accepts more context: 1.0M against 1M tokens.