Chinese AI lab’s chat assistant and low-cost API, built on the DeepSeek V4 model family with DeepThink reasoning and web search.
- API prices are very low, with off-peak rates at half of peak
- Cheap cache-hit pricing for repeated prompts
- DeepThink reasoning and web search built into the chat
- API supports web search and fetch
- Peak-hour API pricing doubles costs during set weekday windows
- Data is processed by a China-based provider, which some organizations restrict
- Few native integrations with office and productivity suites
Developed by the Chinese AI lab of the same name, DeepSeek is both a chat assistant and a developer platform. The company draws attention mainly for pricing: its API costs a fraction of most frontier competitors, and the chat product does not have a paid subscription tier.
The current lineup consists of two API models. deepseek-flash points to DeepSeek V4.1 Flash (version 1017), which the company describes as much stronger at project-level development work, and deepseek-v4-pro serves the larger V4 Pro model. In the chat interface, users can switch on DeepThink for step-by-step reasoning and Search for web results, and the assistant is available on the web and through mobile apps. DeepSeek also offers a desktop tool called DeepSeek Harness. On the API side, rates differ between peak and off-peak hours: off-peak is half the peak price, and cache hits on repeated input are billed far below fresh input. The API also supports web search and fetch.
The best fit is cost-sensitive work: developers building agents or batch pipelines, students, and anyone who wants a capable reasoning model without paying a monthly fee. Organizations should review data-handling terms before sending confidential material, since the service is operated from China. The chat product also lacks the deep office-suite integrations that Google and Microsoft-linked assistants offer, so it works best as a standalone tool.
