DeepSeek

DeepSeek is the most consequential Chinese model of the past two years. It reaches close to frontier-level reasoning while charging a small fraction of what comparable APIs cost — for individual developers and small teams, that difference often decides whether an idea is viable at all.

The weights are open, so it can be self-hosted. Where data cannot leave your own network, that is not a nice-to-have but the deciding factor. Its Chinese is natural, and it holds context across long Chinese documents more reliably than most international models. The web chat and mobile app are free, and both are reachable from mainland China without any additional setup.

The gap is in ecosystem: no plugin system, weaker multimodal capability than GPT or Gemini, and a fairly plain web interface. It suits “give me a correct answer” or “write this function” far better than workflows that need to orchestrate external tools.

Key features

• Deep-thinking mode: Shows its reasoning before giving an answer — good for maths, logic and involved analysis.
• Web search: Pulls in web results as grounding when you need recent information.
• File reading: Upload documents or images; it extracts the text and lets you summarise or ask questions about it.
• Open API: Uses an interface format compatible with the common standard, so existing code can often switch over by changing a few settings.
• Open weights: Download the models and run them on your own servers, keeping data entirely in-house.

How to use

1. Go to deepseek.com for the web chat, or install the official app from your app store.
2. Sign up with a phone number or another supported login.
3. Ask your question; turn on deep thinking for rigorous reasoning and web search when you need fresh information.
4. Developers can create an API key on the official platform and pay per use.
5. Teams that need a private deployment can download the weights from the open-source community and host them.

Best for

• Maths, logic and coding problems: the visible reasoning in deep-thinking mode can be checked step by step.
• Cost-sensitive AI products: prototypes and batch jobs run at a very low API cost.
• Enterprises whose data cannot leave the internal network: open weights allow fully private deployment.
• Long Chinese texts: natural Chinese and stable handling of long context.

Strengths and limitations

Strengths

• Reasoning close to the frontier at a far lower price.
• Open weights that can be deployed privately.
• Strong Chinese, free web access, and direct availability in mainland China.

Limitations

• No plugin system, so it is a poor fit for complex workflows that call external tools.
• Weak multimodal ability; image understanding and generation trail GPT and Gemini.
• A plain web interface, and responses can be slow or show a “server busy” message at peak times.