Gemini 3.5 Flash vs GPT Realtime
Gemini 3.5 Flash and GPT Realtime are both current production-tier models. Gemini 3.5 Flash is meaningfully cheaper at $1.5 / $9 per 1M. Gemini 3.5 Flash has a 1.0M context window — about 8× the 128k of GPT Realtime. Gemini 3.5 Flash leads on coding, reasoning, general knowledge.
Specs side by side
| Metric | Google Gemini 3.5 Flash | OpenAI GPT Realtime |
|---|---|---|
| Input price (per 1M) | $1.5 | $4 |
| Output price (per 1M) | $9 | $16 |
| Context window | 1.0M tokens | 128k tokens |
| Speed tier | fast | ultra |
| Open weights | No | No |
| EU region | Yes | Yes |
| Free tier | Google AI Studio | No |
| Prompt caching | Yes | No |
| Vision input | Yes | No |
| Extended thinking | Yes | No |
When to choose each
Choose Gemini 3.5 Flash if…
- Cost is a priority ($1.5 / $9 per 1M vs $4 / $16 per 1M)
- You need 1.0M context (8× more than GPT Realtime)
- HIPAA eligibility is required
- You need image input / vision
- You want a free tier for prototyping
- Coding is central to your workload
- Reasoning is central to your workload
Choose GPT Realtime if…
- You need realtime speech-to-speech
Benchmark delta
Gemini 3.5 Flash leads on
- Coding
- Reasoning
- General knowledge
- Long-context retrieval
- Instruction following
- Multilingual
- Tool use
GPT Realtime leads on
GPT Realtime has no meaningful benchmark lead in this pair.
FAQ — Gemini 3.5 Flash vs GPT Realtime
Gemini 3.5 Flash vs GPT Realtime — which is better?
Gemini 3.5 Flash and GPT Realtime are both current production-tier models. Gemini 3.5 Flash is meaningfully cheaper at $1.5 / $9 per 1M. Gemini 3.5 Flash has a 1.0M context window — about 8× the 128k of GPT Realtime. Gemini 3.5 Flash leads on coding, reasoning, general knowledge. The right pick depends on your use case — see "When to choose each" above for a data-driven decision.
How does Gemini 3.5 Flash pricing compare to GPT Realtime?
Gemini 3.5 Flash costs $1.5 / $9 per 1M vs GPT Realtime at $4 / $16 per 1M. Gemini 3.5 Flash is cheaper on output tokens by roughly 78%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does Gemini 3.5 Flash or GPT Realtime have the bigger context window?
Gemini 3.5 Flash has a 1.0M-token context window — 8× the 128k context of GPT Realtime. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for Gemini 3.5 Flash or GPT Realtime?
Gemini 3.5 Flash: yes — Reduced daily quota via AI Studio for prototyping. GPT Realtime: no — Paid-only.
Which is better for coding — Gemini 3.5 Flash or GPT Realtime?
Gemini 3.5 Flash leads on coding benchmarks (Gemini 3.5 Flash: 91/100, GPT Realtime: 78/100). For production coding agents also weigh tool-use performance — Gemini 3.5 Flash scores 90, GPT Realtime scores 84.