DeepSeek

DeepSeek is built by High-Flyer, a Chinese quantitative hedge fund that decided to compete with OpenAI and Anthropic — and succeeded. DeepSeek-V3 was trained using roughly 2,000 Nvidia H800 GPUs at an estimated cost of $5.6 million, compared to the $100 million-plus and 16,000+ GPUs that leading Western labs have committed to comparable projects. The announcement shook markets in January 2025: Nvidia shares dropped sharply as investors questioned the assumed requirement for massive GPU clusters.

The chat interface at chat.deepseek.com is completely free with no query limits on the web app. The flagship DeepThink mode (now powered by DeepSeek-V4-Pro) applies visible chain-of-thought reasoning — the model shows its thinking process step by step before delivering a final answer. This is functionally comparable to leading Western reasoning models but costs nothing for consumer use. DeepThink mode excels at coding problems, competitive mathematics, multi-step logic puzzles, and research synthesis tasks.

DeepSeek's current models, V4-Flash and V4-Pro, use a Mixture-of-Experts (MoE) architecture that routes each query to specialized sub-networks rather than running the full model weight, keeping inference costs low. V4-Flash API pricing starts at $0.0028 per million cache-hit input tokens (up to $0.14 per million on a cache miss) and $0.28 per million output tokens — among the cheapest frontier-class APIs available. V4-Pro, the flagship reasoning variant, runs $0.435-$0.87 per million tokens depending on cache state and direction.

In coding benchmarks, DeepSeek-V4-Pro remains competitive with leading Western frontier models on evaluations including HumanEval and LiveCodeBench. For coding-heavy or math-heavy workflows, DeepSeek is a credible free alternative to paid coding assistants.

Users should understand the privacy tradeoffs. Data is processed on servers in China, and the platform is operated by a Chinese company subject to Chinese data regulations. The US Navy, Italian data regulator, and several other government bodies have restricted or banned DeepSeek use on government devices. For personal use, research, and coding tasks without sensitive data, these concerns are manageable. For enterprise or regulated-industry workloads, users should review their compliance requirements before proceeding.

For developers, DeepSeek offers an OpenAI-compatible API, meaning existing code using the OpenAI Python SDK can switch to DeepSeek with minimal changes. The API supports function calling, JSON mode, and multi-turn conversations. File uploads and web search are available in the free chat interface. DeepSeek-V4-Flash has already reached public beta with substantially enhanced agent capabilities, while V4-Pro remains the flagship reasoning model.