comparison
GPT-5.5 vs Gemini 3.1 Pro
Token pricing, context window and real monthly cost, side by side. Gemini 3.1 Pro is the cheaper of the two for a typical workload — about 2.5× less.
| metric | GPT-5.5 | Gemini 3.1 Pro |
|---|---|---|
| Input / 1M | $5.00 | $2.00 |
| Output / 1M | $30.00 | $12.00 |
| Context | 1.1M | 1.0M |
| Cost @ typical workload | $4,500/mo | $1,800/mo |
| Modality | text + image | text + image + audio + video |
| Price source | list | list |
| Provider | OpenAI |
Snapshot . Cost uses a typical workload; tune it in the calculator. How we measure →
Which should you pick?
On a typical workload, Gemini 3.1 Pro costs $1,800/mo against GPT-5.5's $4,500/mo — roughly 2.5× cheaper. But the ranking depends on your output-to-input ratio: output is the pricier direction for both, so an output-heavy job (code generation, long answers) widens the gap while an input-heavy one (summarization, retrieval) narrows it. If you need to fit more in a single prompt, GPT-5.5 has the larger 1.1M-token window (~1,575 pages).
These are list and routed market prices, not measured outcomes. Two models at the same rate can still cost different amounts to finish the same task, because verbose or reasoning-heavy models emit more tokens. That gap is exactly what measured cost-per-task captures.
Frequently asked questions
Is GPT-5.5 or Gemini 3.1 Pro cheaper?
For a typical workload (1,500 input + 500 output tokens × 200,000 requests/month), Gemini 3.1 Pro costs $1,800/mo versus $4,500/mo for GPT-5.5 — about 2.5× less. Because output is priced higher than input, the winner can flip if your workload writes much more or less than this; check your own numbers in the calculator.
What's the main difference between GPT-5.5 and Gemini 3.1 Pro?
On price, GPT-5.5 is $5.00/$30.00 per 1M (in/out) and Gemini 3.1 Pro is $2.00/$12.00. GPT-5.5 has the larger context window at 1.1M tokens.
More comparisons
- GPT-5.5 vs GPT-5.4
- GPT-5.5 vs GPT-5.4 mini
- GPT-5.5 vs GPT-5.4 nano
- GPT-5.5 vs gpt-oss-120b
- Claude Fable 5 vs GPT-5.5
- GPT-5.5 vs Claude Opus 4.8
Related
- GPT-5.5 and Gemini 3.1 Pro — full specs and price history.
- API cost calculator — compare on your own workload.
- All comparisons — the full head-to-head index.