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DeepSeek V4 Pro vs GPT-5.4 Mini: which API costs less?

Averaged across three realistic workloads, DeepSeek V4 Pro is about 83% cheaper than GPT-5.4 Mini. Below: raw rates and side-by-side monthly costs, computed from prices verified 2026-07-05 (we track what you are billed today, promos included).

Rates per 1M tokens

ModelInputOutputCached input
DeepSeek V4 ProDeepSeek$0.435$0.870$0.015
GPT-5.4 MiniOpenAI$0.750$4.50

Monthly cost, side by side

WorkloadDeepSeek V4 ProGPT-5.4 MiniDifference

Customer-support chatbot

2M input + 0.5M output tokens/month, 60% of input served from prompt cache

$0.800$3.75DeepSeek V4 Pro79%

RAG / document Q&A

20M input + 1M output tokens/month, 70% cached (shared context)

$3.68$19.50DeepSeek V4 Pro81%

Agentic coding assistant

50M input + 5M output tokens/month, 80% cached (long sessions)

$9.28$60.00DeepSeek V4 Pro85%

Your traffic looks different? Run your own numbers in the calculator.

FAQ

Which is cheaper: DeepSeek V4 Pro or GPT-5.4 Mini?

Across three realistic workloads (chatbot, RAG, agent), DeepSeek V4 Pro works out about 83% cheaper than GPT-5.4 Mini on average. Raw rates: DeepSeek V4 Pro $0.435/$0.870 per 1M tokens vs GPT-5.4 Mini $0.750/$4.50. Verified 2026-07-05.

Does prompt caching change the comparison?

Yes — cached input costs $0.015 on DeepSeek V4 Pro and the full input rate on GPT-5.4 Mini (no cache discount listed). 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.