GPT-5 Nano vs Grok 4.3
How do these models stack up? Below is an expert side-by-side comparison of specifications, context window capacity, live pricing per million tokens, and standardized benchmark scores for GPT-5 Nano and Grok 4.3.
GPT-5 Nano
GPT-5-Nano is the smallest and fastest variant in the GPT-5 system, optimized for developer tools, rapid interactions, and ultra-low latency environments. While limited in reasoning depth compared to its larger...
Grok 4.3
Grok 4.3 is a reasoning model from xAI. It accepts text and image inputs with text output, and is suited for agentic workflows, instruction-following tasks, and applications requiring high factual...
Technical Specifications
| Specification | GPT-5 Nano | Grok 4.3 |
|---|---|---|
| Provider | OpenAI | xAI |
| Context Window | 400,000 tokens | 1,000,000 tokens |
| Agent Suitability | N/A | 87/100 |
| Time to First Token (TTFT) | N/A | 400 ms |
| Deployment Model | managed api | managed api |
| Production Stability | stable | stable |
| API Available | Yes | Yes |
| Released Date | 2025-08-07 | 2026-04-30 |
API Pricing Comparison
Input Price per Million Tokens
GPT-5 Nano
$0.05
Grok 4.3
$1.25
Output Price per Million Tokens
GPT-5 Nano
$0.40
Grok 4.3
$2.50
Want to test both models live?
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Benchmark Performance Metrics
Scores show the raw performance percentages verified across key evaluation suites. Higher bars indicate superior accuracy and capability in that domain.
GPT-5 Nano Quirks & Gotchas
No developer gotchas reported.
Grok 4.3 Quirks & Gotchas
- ▸Strong coding performance — competitive with Claude Sonnet at similar price point
- ▸Upgrade to Grok 4.20 for improved reasoning and tool calling