Gemini 2.5 Pro vs Gemini 3.1 Pro Preview
A side-by-side comparison of two multimodal models — real specs, pricing, strengths and weaknesses, and a clear verdict on which to choose. Kept current by our agents.
Quick verdict: which should you choose?
Choose Gemini 2.5 Pro if you need
- ✓Choose Gemini 3.1 Pro Preview if you need higher intelligence (46.5 index) for mastering complex multimodal reasoning.
- ✓Choose Gemini 3.1 Pro Preview if you need strong large-scale document analysis with native audio/image/video/text support.
- ✓Choose Gemini 3.1 Pro Preview if you need maximum context handling verified on demanding tasks despite potential inconsistencies.
Choose Gemini 3.1 Pro Preview if you need
- ✓Choose Gemini 2.5 Pro if you need faster output speed at 132.31 t/s versus 122.18 t/s.
- ✓Choose Gemini 2.5 Pro if you need lower pricing at $10 per 1M tokens versus $12.
- ✓Choose Gemini 2.5 Pro if you need efficient handling of complex multi-part files with very large context inputs.
Verdict
Gemini 3.1 Pro Preview leads in intelligence for complex multimodal tasks with its 46.5 index versus 27, while Gemini 2.5 Pro offers modestly higher speed and lower price at identical 1M context. A edges out for advanced reasoning and document analysis despite preview inconsistencies, whereas B suits cost-sensitive or speed-prioritized workloads. Both share native multi-modality support but differ mainly in performance metrics and reliability notes.
Gemini 2.5 Pro vs Gemini 3.1 Pro Preview: side by side
| Spec | Gemini 2.5 Pro | Gemini 3.1 Pro Preview | Winner |
|---|---|---|---|
| Intelligence | 27 | 46.5 | Gemini 3.1 Pro Preview |
| Output speed | 132 t/s | 122 t/s | Gemini 2.5 Pro |
| Output price | $10.00/1M | $12.00/1M | Gemini 2.5 Pro |
| Context | 1049K | 1049K | Tie |
| Params | — | — | Tie |
| Provider | Tie |
Detailed analysis
Intelligence
Winner: Gemini 3.1 Pro PreviewGemini 3.1 Pro Preview scores substantially higher at 46.5 intelligence index compared to 27 for Gemini 2.5 Pro. This supports stronger performance on complex multimodal tasks and large-scale document analysis per the listed strengths.
Speed
Winner: Gemini 2.5 ProGemini 2.5 Pro delivers higher output speed of 132.31 tokens per second against 122.18 for Gemini 3.1 Pro Preview. However, its limitations note higher latency risks on very large multimodal inputs.
Pricing
Winner: Gemini 2.5 ProGemini 2.5 Pro costs $10 per million tokens, undercutting Gemini 3.1 Pro Preview at $12 per million. Both share the same 1,048,576 token context window.
Multimodal Capabilities
Winner: TieBoth models provide native support for multiple modalities including text with visual and audio data at identical context sizes. Gemini 3.1 Pro Preview explicitly adds video while Gemini 2.5 Pro emphasizes complex multi-part file handling.
Gemini 2.5 Pro
Pros
- +Very large context window for extended inputs
- +Native support for multiple modalities in one model
- +Strong integration of text with visual and audio data
Cons
- –Higher latency on very large multimodal inputs
- –Performance can vary with extremely long contexts
- –Dependent on Google infrastructure for access
Gemini 3.1 Pro Preview
Pros
- +Handles up to 1M token contexts
- +Native support for audio, image, video, and text
- +Strong integration of multiple modalities
Cons
- –Preview model may show inconsistent outputs
- –High resource use with maximum context
- –Requires verification on complex tasks
Summary: Gemini 2.5 Pro vs Gemini 3.1 Pro Preview
Select Gemini 3.1 Pro Preview for intelligence-driven multimodal work such as complex analysis despite its preview limitations. Opt for Gemini 2.5 Pro when prioritizing speed and cost efficiency on extended inputs. Both remain proprietary Google models with equivalent context capacity.
Frequently asked questions
Gemini 3.1 Pro Preview is stronger overall due to its much higher intelligence index of 46.5, making it preferable for complex reasoning despite higher cost.