Gemini 3.5 Flash vs Grok 4.5
Gemini 3.5 Flash 
Grok 4.5 Verdict
- Gemini 3.5 Flash (medium) and Grok 4.5 are level on quality (63.9 vs 63.4).
- Gemini 3.5 Flash (medium) is stronger in agents & tools, composite, human preference, instruction following, multimodal.
- Grok 4.5 is stronger in coding, knowledge, long context, reasoning.
- They cost about the same ($3.00 per 1M blended).
- Gemini 3.5 Flash (medium) streams 3.8× faster (209 vs 56 tokens per second).
| Metric | Gemini 3.5 Flash (medium) | Grok 4.5 |
|---|---|---|
| BenchLeader Index | 63.9 | 63.4 |
| Agents & tools score | 67.8 | 58.6 |
| Coding score | 58.9 | 59.9 |
| Composite score | 71.4 | 66.0 |
| Human preference score | 67.4 | 66.9 |
| Instruction following score | 72.2 | – |
| Knowledge score | 73.9 | 76.0 |
| Long context score | 63.6 | 66.2 |
| Multimodal score | 67.6 | 64.8 |
| Reasoning score | 66.8 | 68.9 |
| Blended price $/M | $3.38 | $3.00 |
| Output speed | 209 tok/s | 56 tok/s |
| Time to first answer | 17.0 s | 12.7 s |
| Context window | 1M | 500k |
| SimpleBench | – | 70.0% |
| WeirdML | – | 46.4% |
| APEX-Agents | – | 34.2% |
| FrontierCode | – | 42.4% |
| Epoch Capabilities Index | – | 153.9 |
| LMArena Text | 1476 | 1471 |
| LMArena Hard Prompts | 1493 | 1495 |
| LMArena Coding | 1503 | 1523 |
| LMArena WebDev | 1491 | 1556 |
| LMArena Vision | 1306 | 1291 |
| LMArena Agent | – | 3.9 |
| LiveBench | – | 75.8% |
| LiveBench Reasoning | – | 87.2% |
| LiveBench Coding | – | 68.6% |
| LiveBench Agentic Coding | – | 56.5% |
| LiveBench Mathematics | – | 90.8% |
| LiveBench Data Analysis | – | 73.0% |
| LiveBench Language | – | 82.8% |
| AA Intelligence Index | 33.6 | 39.1 |
| IFBench | 74.6% | – |
| AA-LCR | 74.3% | 79.3% |
| MMMU-Pro | 83.9% | 80.4% |
| AA-Omniscience | 20.8 | 25.3 |
| Terminal-Bench Hard | 39.4% | – |
| GPQA Diamond (AA) | 92.1% | 93.1% |
| Humanity's Last Exam (AA) | 41.3% | 42.7% |
| SciCode (AA) | – | 55.0% |
| τ²-Bench Telecom (AA) | 95.6% | – |
| Kagi LLM Benchmark | – | 83.5% |
Data as of 2026-09-09. Best configuration of each model; every score links to its source on the model pages.