DeepSeek V4 Pro vs DeepSeek V4.1 Flash: which API costs less?
Averaged across three realistic workloads, DeepSeek V4.1 Flash is about 74% cheaper than DeepSeek V4 Pro. Below: raw rates and side-by-side monthly costs, computed from prices verified 2026-10-17 (we track what you are billed today, promos included).
Rates per 1M tokens
| Model | Input | Output | Cached input |
|---|---|---|---|
| DeepSeek V4 ProDeepSeek | $1.32 | $3.96 | $0.044 |
| DeepSeek V4.1 FlashDeepSeek | $0.300 | $1.20 | $0.006 |
DeepSeek V4 Pro: Peak-hour price (01-04 and 06-10 UTC, Mon-Fri); off-peak costs half. DeepSeek V4.1 Flash: Peak-hour price (01-04 and 06-10 UTC, Mon-Fri); off-peak costs half. Replaced DeepSeek V4 Flash.
Monthly cost, side by side
| Workload | DeepSeek V4 Pro | DeepSeek V4.1 Flash | Difference |
|---|---|---|---|
Customer-support chatbot 2M input + 0.5M output tokens/month, 60% of input served from prompt cache | $3.09 | $0.847 | DeepSeek V4.1 Flash −73% |
RAG / document Q&A 20M input + 1M output tokens/month, 70% cached (shared context) | $12.50 | $3.08 | DeepSeek V4.1 Flash −75% |
Agentic coding assistant 50M input + 5M output tokens/month, 80% cached (long sessions) | $34.76 | $9.24 | DeepSeek V4.1 Flash −73% |
Your traffic looks different? Run your own numbers in the calculator.
FAQ
Which is cheaper: DeepSeek V4 Pro or DeepSeek V4.1 Flash?
Across three realistic workloads (chatbot, RAG, agent), DeepSeek V4.1 Flash works out about 74% cheaper than DeepSeek V4 Pro on average. Raw rates: DeepSeek V4 Pro $1.32/$3.96 per 1M tokens vs DeepSeek V4.1 Flash $0.300/$1.20. Verified 2026-10-17.
Does prompt caching change the comparison?
Yes — cached input costs $0.044 on DeepSeek V4 Pro and $0.006 on DeepSeek V4.1 Flash. Our scenario numbers already include realistic cache hit rates.
Is cheaper always better?
No. Price is one axis — model capability, context window and latency differ. This page answers only the cost question; benchmark quality on your own tasks before switching.