GPT-5 Nano vs Grok 4.20
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 Nano if you need
- ✓faster responses at 162.33 tokens per second
- ✓lower cost at $0.4 per million tokens
- ✓efficient handling of 400k-token contexts with lightweight design
- ✓practical extended document tasks where top-tier reasoning depth is not required
Choose Grok 4.20 if you need
- ✓highest intelligence at index 37 for complex multimodal reasoning
- ✓extreme 2-million-token context windows
- ✓native multimodal integration across very large inputs
- ✓maximum-scale document and file analysis where latency and cost are secondary
Verdict
Grok 4.20 leads in raw intelligence and maximum context size while GPT-5 Nano wins on speed and price. Grok's 37 intelligence index and 2M-token window suit the most demanding multimodal document tasks, but its higher cost and slower output make GPT-5 Nano the practical choice for high-volume or budget-sensitive workloads. Both models share text-image-file support with no audio or video capabilities.
GPT-5 Nano vs Grok 4.20: side by side
| Spec | GPT-5 Nano | Grok 4.20 | Winner |
|---|---|---|---|
| Intelligence | 19.9 | 37 | Grok 4.20 |
| Output speed | 162 t/s | 134 t/s | GPT-5 Nano |
| Output price | $0.40/1M | $2.50/1M | GPT-5 Nano |
| Context | 400K | 2000K | Grok 4.20 |
| Params | — | — | Tie |
| Provider | OpenAI | xAI | Tie |
Detailed analysis
Intelligence
Winner: Grok 4.20Grok 4.20 scores 37 on the intelligence index compared with GPT-5 Nano's 19.9. This gap indicates stronger performance on complex reasoning tasks. GPT-5 Nano's limitations note trade-offs in advanced task performance.
Speed
Winner: GPT-5 NanoGPT-5 Nano outputs at 162.33 tokens per second versus Grok 4.20's 134.34. Its lightweight design supports faster responses. Grok notes that very large contexts can increase latency.
Pricing
Winner: GPT-5 NanoGPT-5 Nano costs $0.4 per million tokens while Grok 4.20 costs $2.5. The five-fold price difference favors GPT-5 Nano for high-volume use. Both are proprietary models from established providers.
Context Window
Winner: Grok 4.20Grok 4.20 supports up to 2 million tokens versus GPT-5 Nano's 400,000. This gives Grok a clear advantage for extremely large multimodal inputs. GPT-5 Nano still handles very large contexts efficiently within its limit.
GPT-5 Nano
Pros
- +Handles very large contexts efficiently
- +Supports text, image, and file inputs
- +Lightweight design for faster responses
Cons
- –Lower capability depth than full-scale models
- –May struggle with highly complex reasoning
- –Trade-off in advanced task performance
Grok 4.20
Pros
- +Handles extremely large contexts up to 2M tokens
- +Native support for text, image, and file inputs
- +Multimodal integration in a single model
Cons
- –No audio or video modality support
- –Very large context can increase latency
- –Performance depends on input quality and structure
Summary: GPT-5 Nano vs Grok 4.20
Choose GPT-5 Nano when speed and cost matter most for large but not extreme contexts. Select Grok 4.20 when maximum intelligence and the largest possible context windows are required. The decision hinges on whether the workload prioritizes throughput and affordability or depth and scale.
Frequently asked questions
Grok 4.20 is stronger on intelligence and context size; GPT-5 Nano is better on speed and price. Neither dominates every dimension.