# Gemini 3.1 Pro Preview vs Gemini 4 Argon

As of October 21, 2026, Gemini 3.1 Pro Preview and Gemini 4 Argon cost the same per input token ($2.00 per 1M), but Gemini 3.1 Pro Preview costs 20% more per output token ($12.00 vs $10.00), and both have a 1M-token context window. Gemini 4 Argon's price is introductory through November 30, 2026.

- Page: https://models.litellm.ai/compare/gemini-3.1-pro-preview-vs-gemini-4-argon
- Gemini 3.1 Pro Preview: https://models.litellm.ai/models/gemini-3.1-pro-preview
- Gemini 4 Argon: https://models.litellm.ai/models/gemini-4-argon

## Side by side

| | Gemini 3.1 Pro Preview | Gemini 4 Argon |
|---|---|---|
| Input, per 1M tokens | $2.00 | $2.00 |
| Output, per 1M tokens | $12.00 | $10.00 |
| Cache read, per 1M tokens | $0.20 | $0.10 |
| Cache write, per 1M tokens | – | – |
| Context window | 1,048,576 tokens | 1,048,576 tokens |
| Max output | 65,536 tokens | 1,048,576 tokens |
| Image input | Yes | Yes |
| Tool calling | Yes | Yes |
| Structured output (JSON) | Yes | Yes |
| Prompt caching | Yes | Yes |
| Reasoning | Yes | Yes |
| Providers on LiteLLM | 4 | 3 |
| Price shown is from | Google AI Studio | Google AI Studio, introductory until November 30, 2026 |
| Added to LiteLLM | February 2026 | October 13, 2026 |

Headline prices in USD per 1M tokens, from LiteLLM's model price file.

## Cheapest provider for each

- Gemini 3.1 Pro Preview: Google AI Studio at $2.00 input per 1M tokens (`gemini/gemini-3.1-pro-preview`)
- Gemini 4 Argon: Google AI Studio at $2.00 input per 1M tokens (`gemini/gemini-4-argon`)

## Benchmark scores

| Benchmark | Gemini 3.1 Pro Preview | Gemini 4 Argon |
|---|---|---|
| APEX-Agents (Coding and agents) | 35.1% | 82.4% |
| GPQA Diamond (Reasoning and knowledge) | 94.4% (high) | 96.4% (high) |
| ARC-AGI-2 (Reasoning and knowledge) | 77.1% | 91.3% (high) |
| SimpleQA Verified (Reasoning and knowledge) | 73.5% (high) | 76.0% (high) |
| FrontierMath (tiers 1-3) (Math) | 59.6% | 86.0% (high) |
| FrontierMath (tier 4) (Math) | 26.8% | 78.0% (high) |
| OTIS Mock AIME 2024-2025 (Math) | 95.6% | 100.0% (high) |

From the Epoch AI Benchmarking Hub (https://epoch.ai/benchmarks), CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/), data as of October 13, 2026: Epoch's own runs and results it collects from each benchmark's leaderboard. Higher is better.

## When to pick which

- Gemini 4 Argon: Costs 17% less per output token: $10.00 vs $12.00 per 1M.
- Gemini 4 Argon: Returns up to 1,048,576 tokens per response, vs 65,536.

## FAQ

### Which is cheaper, Gemini 3.1 Pro Preview or Gemini 4 Argon?

Gemini 4 Argon is cheaper at 3 input tokens per output token: $4.00 per 1M tokens blended ($2.00 input, $10.00 output), versus $4.50 ($2.00 and $12.00) for Gemini 3.1 Pro Preview, as of October 21, 2026.

### Which has the larger context window, Gemini 3.1 Pro Preview or Gemini 4 Argon?

Both have a 1,048,576-token context window.

### Can I switch from Gemini 3.1 Pro Preview to Gemini 4 Argon without changing my code?

Yes. Through LiteLLM both use the OpenAI format, so switching means changing the model name from "gemini/gemini-3.1-pro-preview" to "gemini/gemini-4-argon", or pointing a LiteLLM gateway model alias at the other model. You can also use one as a fallback for the other.