Gemini 3 Flash vs Grok 4.5
Gemini 3 Flash 
Grok 4.5 Verdict
- Grok 4.5 leads on quality: 63.5 vs 61.6.
- Gemini 3 Flash (thinking) is stronger in agents & tools, instruction following.
- Grok 4.5 is stronger in composite, knowledge, long context, multimodal, coding, human preference, reasoning.
- Gemini 3 Flash (thinking) is 2.7× cheaper ($1.13 vs $3.00 per 1M blended).
- Gemini 3 Flash (thinking) streams 3.5× faster (180 vs 52 tokens per second).
| Metric | Gemini 3 Flash (thinking) | Grok 4.5 |
|---|---|---|
| BenchLeader Index | 61.6 | 63.5 |
| Agents & tools score | 67.4 | 58.6 |
| Composite score | 62.3 | 66.2 |
| Instruction following score | 75.4 | – |
| Knowledge score | 69.0 | 76.2 |
| Long context score | 65.5 | 66.2 |
| Multimodal score | 64.4 | 64.9 |
| Coding score | – | 59.8 |
| Human preference score | – | 67.2 |
| Reasoning score | – | 69.2 |
| Blended price $/M | $1.13 | $3.00 |
| Output speed | 180 tok/s | 52 tok/s |
| Time to first answer | 6.1 s | 13.6 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 | – | 1471 |
| LMArena Hard Prompts | – | 1495 |
| LMArena Coding | – | 1523 |
| LMArena WebDev | – | 1556 |
| LMArena Vision | – | 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 | 26.3 | 39.1 |
| IFBench | 78.0% | – |
| AA-LCR | 78.0% | 79.3% |
| MMMU-Pro | 79.9% | 80.4% |
| AA-Omniscience | 10.1 | 25.3 |
| Terminal-Bench Hard | 38.6% | – |
| GPQA Diamond (AA) | 89.8% | 93.1% |
| Humanity's Last Exam (AA) | 36.6% | 42.7% |
| SciCode (AA) | – | 55.0% |
| τ²-Bench Telecom (AA) | 80.4% | – |
| Kagi LLM Benchmark | – | 83.5% |
Data as of 2026-09-10. Best configuration of each model; every score links to its source on the model pages.
Gemini 3 Flash vs Grok 4.5: questions
- Is Gemini 3 Flash better than Grok 4.5?
- Grok 4.5 leads on quality: 63.5 vs 61.6. The BenchLeader Index combines every independent quality benchmark; Grok 4.5 is ahead overall as of 2026-09-10, but check the category scores for your use.
- Is Gemini 3 Flash better than Grok 4.5 for agentic tasks?
- Gemini 3 Flash scores higher in agentic tasks (67 vs 59 on the category index, where 50 is average).
- Which is cheaper, Gemini 3 Flash or Grok 4.5?
- Gemini 3 Flash is cheaper: $1.13 against $3.00 per million tokens, blended at three input tokens per output token.
- Which is faster, Gemini 3 Flash or Grok 4.5?
- Gemini 3 Flash streams faster: 180 against 52 output tokens per second.
- Which has the larger context window?
- Gemini 3 Flash accepts more context: 1M against 500k tokens.