GPT-5.1 vs GPT-5 Nano
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-5.1 if you need
- ✓higher intelligence index of 27.4 for demanding multimodal tasks
- ✓strong multimodal integration beyond basic input support
- ✓maximum capability when context latency is acceptable
- ✓scenarios where verified performance depth outweighs cost
Choose GPT-5 Nano if you need
- ✓much higher output speed of 170.06 t/s for rapid responses
- ✓dramatically lower price at $0.4 per million tokens
- ✓lightweight handling of large contexts with extended documents
- ✓practical efficiency when advanced reasoning depth is secondary
Verdict
GPT-5.1 leads on raw intelligence (27.4 vs 26.8) and claims stronger multimodal integration, while GPT-5 Nano wins decisively on speed (170 vs 116 t/s) and price ($0.4 vs $10 per million tokens). Both share identical 400k context and text/image/file support from OpenAI, but Nano's lightweight design trades depth for efficiency. GPT-5.1 suits complex reasoning needs; Nano fits high-volume, cost-sensitive workloads.
GPT-5.1 vs GPT-5 Nano: side by side
| Spec | GPT-5.1 | GPT-5 Nano | Winner |
|---|---|---|---|
| Intelligence | 27.4 | 26.8 | GPT-5.1 |
| Output speed | 116 t/s | 170 t/s | GPT-5 Nano |
| Output price | $10.00/1M | $0.40/1M | GPT-5 Nano |
| Context | 400K | 400K | Tie |
| 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 compared to 26.8 for GPT-5 Nano. This edge aligns with its described strong multimodal integration. Nano's lower score matches its noted trade-off in advanced task performance and complex reasoning.
Speed
Winner: GPT-5 NanoGPT-5 Nano delivers 170.06 tokens per second versus 115.83 for GPT-5.1. Its lightweight design explicitly supports faster responses. GPT-5.1 notes potential latency at maximum context as a counterpoint.
Pricing
Winner: GPT-5 NanoGPT-5 Nano costs $0.4 per million tokens while GPT-5.1 costs $10 per million. The 25x price difference favors Nano for high-volume use. Both are proprietary OpenAI models with no other cost details provided.
Context & Modalities
Winner: TieBoth models share a 400000 token context window and native support for text, images, and files. Neither includes audio or video. GPT-5.1 emphasizes very large context while Nano stresses efficient handling of the same size.
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
GPT-5 Nano
Pros
- +Handles very large contexts efficiently
- +Supports text, image, and file inputs
- +Lightweight design for faster responses
- +Practical for extended document tasks
Cons
- –Lower capability depth than full-scale models
- –May struggle with highly complex reasoning
- –Trade-off in advanced task performance
Summary: GPT-5.1 vs GPT-5 Nano
Choose GPT-5.1 when maximum intelligence and integration depth are required despite higher cost and slower speed. Select GPT-5 Nano for speed, affordability, and efficient large-context work where slightly lower capability is acceptable. The choice hinges on whether intelligence or efficiency drives the workload.
Frequently asked questions
GPT-5.1 is better for intelligence-heavy multimodal work while GPT-5 Nano is better for speed and cost efficiency; neither is universally superior.