GPT-4.1 nano vs Grok 4.1 Fast
A direct API-pricing comparison between GPT-4.1 nano and Grok 4.1 Fast. Below: every cost dimension side by side, then the bottom line for a typical workload.
Bottom line
For a typical 5K-in / 1K-out request, GPT-4.1 nano is the cheaper choice at $0.0009 per call — 1.7× less than Grok 4.1 Fast at $0.0015.
| GPT-4.1 nanoOpenAI | Grok 4.1 FastxAI | |
|---|---|---|
| Input / 1M tokens | $0.100 | $0.200 |
| Output / 1M tokens | $0.400 | $0.500 |
| Cached input / 1M | — | — |
| Context window | 1M | 256K |
| Provider | OpenAI | xAI |
Green = cheaper on that line. Prices are estimates from public pricing pages; verify against OpenAI and xAI before relying on them.
Which is cheaper, GPT-4.1 nano or Grok 4.1 Fast?
On output tokens — usually the dominant cost — GPT-4.1 nano charges $0.400 per million versus $0.500 for Grok 4.1 Fast. The right pick depends on your input/output ratio and how much you can serve from cache. Use the calculator to model your exact traffic.