DeepSeek V4 Flash vs Grok 4.1 Fast

DeepSeek against xAI, costed on the same three workloads. DeepSeek V4 Flash is cheaper on all three workloads.

Monthly bill, side by side

WorkloadDeepSeek V4 FlashGrok 4.1 FastDifference
Support chatbot
2,500 six-turn conversations a day
$394 $603 $209 (1.5×)
Document summariser
1,000 single-shot summaries a day
$57.96 $85.20 $27.24 (+47%)
Coding agent
200 twelve-turn sessions a day
$318 $472 $154 (+49%)

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

DeepSeek V4 FlashGrok 4.1 Fast
Input, per 1M tokens$0.14$0.2
Output, per 1M tokens$0.28$0.5
Cached input$0.0028$0.05
Context window1M2M
Maximum output8K2M
Reasoning modelyesyes
Visionnoyes

Run this comparison on your own numbers

Full detail: DeepSeek V4 Flash pricing · Grok 4.1 Fast pricing