Gemini 3.1 Flash vs GPT-5
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for Gemini 3.1 Flash and GPT-5.
Gemini 3.1 Flash
Gemini 3.1 Flash is Google's high-speed, cost-efficient multimodal model in the 3.1 generation, purpose-built for high-volume content synthesis, classification, and intelligent routing at scale. Featuring a 1-million-token context window, it can process large batches of documents, customer data, or multimedia content in a single inference pass, dramatically reducing pipeline complexity. At just $0.25/MTok for input, it is one of the most affordable routes to Google-caliber multimodal AI, making it an ideal backbone for production pipelines, data enrichment workflows, and high-frequency API integrations.
GPT-5
GPT-5 is OpenAI’s most advanced model, offering major improvements in reasoning, code quality, and user experience. It is optimized for complex tasks that require step-by-step reasoning, instruction following, and accuracy...
Technical Specifications
| Specification | Gemini 3.1 Flash | GPT-5 |
|---|---|---|
| Provider | OpenAI | |
| Context Window | 1,000,000 tokens | 400,000 tokens |
| Agent Suitability | 86/100 | 92/100 |
| Time to First Token (TTFT) | 150 ms | 320 ms |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2026-04-20 | 2025-08-07 |
API Pricing Comparison
Input Price per Million Tokens
Gemini 3.1 Flash
$0.25
GPT-5
$1.25
Output Price per Million Tokens
Gemini 3.1 Flash
$1.50
GPT-5
$10.00
Want to test both models live?
Run side-by-side prompt prompts in our dynamic Sandbox. Check execution speeds, latency metrics, and compute actual costs in real-time.
Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
Gemini 3.1 Flash Quirks & Gotchas
- ▸Most cost-effective Google model — ideal for high-volume pipelines
- ▸Context caching available via Vertex AI for repeated document processing
GPT-5 Quirks & Gotchas
- ▸Reliable all-rounder — use as default for most production workflows
- ▸Not recommended for advanced reasoning chains — use o3-mini instead