DeepSeek V4 Flash vs o4-mini

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

Monthly bill, side by side

WorkloadDeepSeek V4 Flasho4-miniDifference
Support chatbot
2,500 six-turn conversations a day
$1,416 $3,985 $2,569 (2.8×)
Document summariser
1,000 single-shot summaries a day
$193 $508 $315 (2.6×)
Coding agent
200 twelve-turn sessions a day
$1,077 $2,891 $1,814 (2.7×)

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 Flasho4-mini
Input, per 1M tokens$0.44$1.1
Output, per 1M tokens$1.32$4.4
Cached input$0.014$0.275
Context window1M200K
Maximum output384K100K
Reasoning modelyesyes
Visionnoyes

Run this comparison on your own numbers

Full detail: DeepSeek V4 Flash pricing · o4-mini pricing