Gemini 3.1 Flash Lite vs GPT-5.1
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 3.1 Flash Lite if you need
- ✓Choose Gemini 3.1 Flash Lite if you need maximum speed (310 t/s) and lowest cost ($1.5/M).
- ✓Choose Gemini 3.1 Flash Lite if you need the largest context window (1,048,576 tokens).
- ✓Choose Gemini 3.1 Flash Lite if you need video alongside text and image support.
- ✓Choose Gemini 3.1 Flash Lite if you need higher intelligence (33.5) in a lightweight package.
Choose GPT-5.1 if you need
- ✓Choose GPT-5.1 if you need native file processing in addition to images and text.
- ✓Choose GPT-5.1 if you need strong multimodal integration within a 400k context.
- ✓Choose GPT-5.1 if your workload stays well below maximum context size.
Verdict
Gemini 3.1 Flash Lite leads on every measured dimension with a higher intelligence index (33.5 vs 27.4), 2.7× faster output speed, 6.7× lower price, and more than double the context length. GPT-5.1 offers native file support and strong multimodal integration but trails in speed, cost, and scale. The lite model is the clear choice for efficiency-focused multimodal workloads while GPT-5.1 remains viable only when file-centric processing is required.
Gemini 3.1 Flash Lite vs GPT-5.1: side by side
| Spec | Gemini 3.1 Flash Lite | GPT-5.1 | Winner |
|---|---|---|---|
| Intelligence | 33.5 | 27.4 | Gemini 3.1 Flash Lite |
| Output speed | 310 t/s | 116 t/s | Gemini 3.1 Flash Lite |
| Output price | $1.50/1M | $10.00/1M | Gemini 3.1 Flash Lite |
| Context | 1049K | 400K | Gemini 3.1 Flash Lite |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: Gemini 3.1 Flash LiteGemini 3.1 Flash Lite scores 33.5 on the intelligence index while GPT-5.1 scores 27.4. The six-point gap favors Gemini for complex multimodal reasoning despite its lite design.
Speed & Latency
Winner: Gemini 3.1 Flash LiteGemini 3.1 Flash Lite delivers 310.24 tokens per second versus GPT-5.1's 115.83 t/s. This makes Gemini more than twice as fast for high-throughput tasks.
Pricing
Winner: Gemini 3.1 Flash LiteGemini 3.1 Flash Lite costs $1.5 per million output tokens while GPT-5.1 costs $10 per million. The 6.7× price advantage strongly favors Gemini for cost-sensitive deployments.
Context & Modalities
Winner: Gemini 3.1 Flash LiteGemini 3.1 Flash Lite provides 1,048,576 tokens of context and supports video; GPT-5.1 offers 400,000 tokens and file support but lacks audio or video. Gemini wins on scale and breadth.
Gemini 3.1 Flash Lite
Pros
- +High speed and low latency
- +Handles very large context windows
- +Broad modality support in a lightweight package
- +Resource-efficient inference
Cons
- –Reduced depth on highly complex reasoning tasks
- –Lite design trades peak capability for speed
- –May require more guidance on nuanced or creative outputs
GPT-5.1
Pros
- +Very large context window
- +Native support for images, text, and files
- +Strong multimodal integration
Cons
- –No audio or video modalities
- –Performance details unverified beyond specs
- –Potential latency with maximum context
Summary: Gemini 3.1 Flash Lite vs GPT-5.1
Gemini 3.1 Flash Lite is the superior option for nearly all multimodal use cases due to superior speed, cost, context, and intelligence scores. GPT-5.1 should be considered only when native file handling is a strict requirement. Most users will achieve better performance and lower cost with Gemini 3.1 Flash Lite.
Frequently asked questions
Gemini 3.1 Flash Lite is better on every quantitative metric provided: intelligence, speed, price, and context length.