Gemini 3.5 Flash vs GPT-5.4 Pro
Gemini 3.5 Flash and GPT-5.4 Pro 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 3× the 400k of GPT-5.4 Pro. Gemini 3.5 Flash leads on long-context retrieval. GPT-5.4 Pro leads on coding, reasoning, general knowledge.
Specs side by side
| Metric | Google Gemini 3.5 Flash | OpenAI GPT-5.4 Pro |
|---|---|---|
| Input price (per 1M) | $1.5 | $30 |
| Output price (per 1M) | $9 | $180 |
| Context window | 1.0M tokens | 400k tokens |
| Speed tier | fast | slow |
| Open weights | No | No |
| EU region | Yes | No |
| Free tier | Google AI Studio | No |
| Prompt caching | Yes | Yes |
| Vision input | Yes | Yes |
| Extended thinking | Yes | Yes |
When to choose each
Choose Gemini 3.5 Flash if…
- Cost is a priority ($1.5 / $9 per 1M vs $30 / $180 per 1M)
- You need 1.0M context (3× more than GPT-5.4 Pro)
- Low latency matters (fast vs slow)
- EU data residency is required
- You want a free tier for prototyping
- Long-context retrieval is central to your workload
Choose GPT-5.4 Pro if…
- Coding is central to your workload
- Reasoning is central to your workload
Benchmark delta
Gemini 3.5 Flash leads on
- Long-context retrieval
GPT-5.4 Pro leads on
- Coding
- Reasoning
- General knowledge
- Tool use
FAQ — Gemini 3.5 Flash vs GPT-5.4 Pro
Gemini 3.5 Flash vs GPT-5.4 Pro — which is better?
Gemini 3.5 Flash and GPT-5.4 Pro 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 3× the 400k of GPT-5.4 Pro. Gemini 3.5 Flash leads on long-context retrieval. GPT-5.4 Pro 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-5.4 Pro?
Gemini 3.5 Flash costs $1.5 / $9 per 1M vs GPT-5.4 Pro at $30 / $180 per 1M. Gemini 3.5 Flash is cheaper on output tokens by roughly 1900%. Both support prompt caching, which reduces effective cost by 80-90% on repeat system prompts.
Does Gemini 3.5 Flash or GPT-5.4 Pro have the bigger context window?
Gemini 3.5 Flash has a 1.0M-token context window — 3× the 400k context of GPT-5.4 Pro. Enough for entire codebases, books, or multi-document RAG.
Is there a free tier for Gemini 3.5 Flash or GPT-5.4 Pro?
Gemini 3.5 Flash: yes — Reduced daily quota via AI Studio for prototyping. GPT-5.4 Pro: no — Paid-only — no free tier.
Which is better for coding — Gemini 3.5 Flash or GPT-5.4 Pro?
GPT-5.4 Pro leads on coding benchmarks (Gemini 3.5 Flash: 91/100, GPT-5.4 Pro: 96/100). For production coding agents also weigh tool-use performance — Gemini 3.5 Flash scores 90, GPT-5.4 Pro scores 94.