Gemini 3.8 Flash vs GPT-5
Gemini 3.8 Flash 
GPT-5 Verdict
- Gemini 3.8 Flash (medium) leads on quality: 63.6 vs 60.8.
- Gemini 3.8 Flash (medium) is stronger in coding, composite, knowledge, long context, multimodal.
- GPT-5 is stronger in agents & tools, human preference, instruction following, maths, reasoning.
- Gemini 3.8 Flash (medium) is 2.3× cheaper ($1.50 vs $3.44 per 1M blended).
- Gemini 3.8 Flash (medium) streams 3.2× faster (269 vs 85 tokens per second).
| Metric | Gemini 3.8 Flash (medium) | GPT-5 |
|---|---|---|
| BenchLeader Index | 63.6 | 60.8 |
| Coding score | 63.8 | 60.9 |
| Composite score | 79.7 | 58.1 |
| Knowledge score | 77.9 | 62.2 |
| Long context score | 68.6 | 65.6 |
| Multimodal score | 68.9 | 59.6 |
| Agents & tools score | – | 51.0 |
| Human preference score | – | 61.7 |
| Instruction following score | – | 65.0 |
| Maths score | – | 72.8 |
| Reasoning score | – | 64.2 |
| Blended price $/M | $1.50 | $3.44 |
| Output speed | 269 tok/s | 85 tok/s |
| Time to first answer | 11.8 s | 60.7 s |
| Context window | 1.0M | 400k |
| Terminal-Bench | – | 49.6% |
| SciCode | 54.4% | 42.9% |
| Remote Labor Index | – | 1.7% |
| WeirdML | – | 39.8% |
| APEX-Agents | – | 18.3% |
| Epoch Capabilities Index | – | 150 |
| LMArena Text | – | 1427 |
| LMArena Hard Prompts | – | 1449 |
| LMArena Coding | – | 1462 |
| LMArena Vision | – | 1232 |
| AA Intelligence Index | 40 | 23.0 |
| IFBench | – | 73.1% |
| AA-LCR | 84.0% | 78.2% |
| MMMU-Pro | 84.2% | 74.2% |
| AA-Omniscience | 28.6 | -8.7 |
| Terminal-Bench Hard | – | 32.6% |
| GPQA Diamond (AA) | 93.5% | 85.3% |
| Humanity's Last Exam (AA) | 42.1% | 28.5% |
| SciCode (AA) | 55.1% | – |
| τ²-Bench Telecom (AA) | – | 84.8% |
| PRBench Finance | – | 51.3% |
| PRBench Legal | – | 49.0% |
| VISTA | – | 49.7% |
| MultiNRC | – | 52.1% |
| TutorBench | – | 55.3% |
| Kagi LLM Benchmark | – | 72.7% |
| IFEval (HELM) | – | 87.5% |
| Omni-MATH (HELM) | – | 64.7% |
| WildBench (HELM) | – | 85.7% |
| MMLU-Pro (HELM) | – | 86.3% |
| GPQA Diamond (HELM) | – | 79.1% |
| HELM Capabilities mean | – | 80.7% |
| Aider Polyglot | – | 88.0% |
| SWE-bench Verified (any scaffold) | – | 75.6% |
Data as of 2026-09-12. Best configuration of each model; every score links to its source on the model pages.
Gemini 3.8 Flash vs GPT-5: questions
- Is Gemini 3.8 Flash better than GPT-5?
- Gemini 3.8 Flash (medium) leads on quality: 63.6 vs 60.8. The BenchLeader Index combines every independent quality benchmark; Gemini 3.8 Flash (medium) is ahead overall as of 2026-09-12, but check the category scores for your use.
- Is Gemini 3.8 Flash better than GPT-5 for coding?
- Gemini 3.8 Flash scores higher in coding (64 vs 61 on the category index, where 50 is average).
- Which is cheaper, Gemini 3.8 Flash or GPT-5?
- Gemini 3.8 Flash is cheaper: $1.50 against $3.44 per million tokens, blended at three input tokens per output token.
- Which is faster, Gemini 3.8 Flash or GPT-5?
- Gemini 3.8 Flash streams faster: 269 against 85 output tokens per second.
- Which has the larger context window?
- Gemini 3.8 Flash accepts more context: 1.0M against 400k tokens.