GPT-4.1 Nano 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 GPT-4.1 Nano if you need
- ✓Higher intelligence index of 27.4 for demanding multimodal reasoning
- ✓Strong multimodal integration across images, text, and files
- ✓Very large 400k context window without nano-size trade-offs
Choose GPT-5.1 if you need
- ✓Faster output at 171.89 t/s and far lower $0.4/1M pricing
- ✓Extremely large 1M+ context for massive inputs
- ✓Efficient OpenAI multimodal architecture when cost and speed matter most
Verdict
GPT-5.1 leads on intelligence with a 27.4 index versus 13, offering stronger multimodal integration for complex tasks. GPT-4.1 Nano wins on speed (171.89 t/s vs 115.83), price ($0.4 vs $10 per 1M), and context size (1,047,576 vs 400,000). Both share native image/text/file support from OpenAI but trade depth for efficiency in the Nano variant.
GPT-4.1 Nano vs GPT-5.1: side by side
| Spec | GPT-4.1 Nano | GPT-5.1 | Winner |
|---|---|---|---|
| Intelligence | 13 | 27.4 | GPT-5.1 |
| Output speed | 172 t/s | 116 t/s | GPT-4.1 Nano |
| Output price | $0.40/1M | $10.00/1M | GPT-4.1 Nano |
| Context | 1048K | 400K | GPT-4.1 Nano |
| Params | — | — | Tie |
| Type | Proprietary | Proprietary | Tie |
| Provider | OpenAI | OpenAI | Tie |
Detailed analysis
Intelligence
Winner: GPT-5.1GPT-5.1 scores 27.4 on the intelligence index while GPT-4.1 Nano scores 13. This gap favors GPT-5.1 for complex multimodal tasks despite both using OpenAI's architecture.
Speed & Pricing
Winner: GPT-4.1 NanoGPT-4.1 Nano delivers 171.89 t/s at $0.4 per 1M tokens versus GPT-5.1's 115.83 t/s at $10 per 1M. The Nano model clearly leads on efficiency metrics.
Context Window
Winner: GPT-4.1 NanoGPT-4.1 Nano provides 1,047,576 tokens compared with GPT-5.1's 400,000. Its larger window supports more extensive multimodal inputs.
Multimodal Capabilities
Winner: TieBoth models natively support images, text, and files with no audio or video. GPT-5.1 emphasizes strong integration while GPT-4.1 Nano highlights its OpenAI multimodal architecture.
GPT-4.1 Nano
Pros
- +Extremely large context window
- +Native support for images, text, and files
- +OpenAI multimodal architecture
Cons
- –Nano size may reduce depth on complex tasks
- –Performance trade-offs for efficiency
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: GPT-4.1 Nano vs GPT-5.1
Select GPT-5.1 when maximum intelligence and integration depth are required. Choose GPT-4.1 Nano for speed, cost efficiency, and the largest context window. Both remain proprietary OpenAI options limited to image/text/file modalities.
Frequently asked questions
GPT-5.1 is stronger on intelligence while GPT-4.1 Nano leads on speed, price, and context size; choice depends on priorities.