GPT-5.4 Nano vs Grok 4.1 Fast
OpenAI against xAI, costed on the same three workloads. Grok 4.1 Fast is cheaper on all three workloads.
Monthly bill, side by side
| Workload | GPT-5.4 Nano | Grok 4.1 Fast | Difference |
|---|---|---|---|
| Support chatbot 2,500 six-turn conversations a day |
$907 | $603 | $304 (1.5×) |
| Document summariser 1,000 single-shot summaries a day |
$103 | $85.20 | $18.00 (+21%) |
| Coding agent 200 twelve-turn sessions a day |
$607 | $472 | $135 (+29%) |
No prompt caching and no batch discount on either side, so the comparison is like for like. Both figures assume 30 days a month.
The rate cards
| GPT-5.4 Nano | Grok 4.1 Fast | |
|---|---|---|
| Input, per 1M tokens | $0.2 | $0.2 |
| Output, per 1M tokens | $1.25 | $0.5 |
| Cached input | $0.02 | $0.05 |
| Context window | 272K | 2M |
| Maximum output | 128K | 2M |
| Reasoning model | yes | yes |
| Vision | yes | yes |
Run this comparison on your own numbers
Full detail: GPT-5.4 Nano pricing · Grok 4.1 Fast pricing