DeepSeek overview: what the Chinese AI assistant offers

DeepSeek is an artificial intelligence company based in Hangzhou, China, and also the name of the chat assistant it offers on the web and in mobile apps for iPhone and Android. The company is backed by a Chinese quantitative investment firm and concentrates on research into large language models, which it publishes openly more often than most of its competitors.

DeepSeek drew worldwide attention when its reasoning model performed close to leading models from other labs on many math and coding benchmarks, while the company reported much lower training costs than the industry expected. The app briefly climbed to the top of download charts in several countries, and the release started a wider discussion about how efficiently capable AI can be built.

The chat assistant looks familiar to anyone who has used ChatGPT: you type a question, attach documents or images so it can read the text in them, and continue with follow-ups. Two switches matter most. A deep-thinking mode makes the assistant work through a problem step by step and shows its reasoning before the final answer, and a search option lets it pull in current information from the web.

Behind the assistant are DeepSeek's own model families. The V series are general-purpose models built on a mixture-of-experts design, which activates only part of a very large network for each request and makes them efficient to run. The R series introduced reasoning models trained heavily with reinforcement learning. Later releases merged these abilities, so one model can answer quickly or think longer depending on the mode. The company has also released specialized models for coding, mathematics and vision.

For developers there is a paid API that follows the same request format as OpenAI's API, so many existing tools and libraries can be pointed at DeepSeek with small changes. The consumer chat itself has been offered free of charge.

Unlike several other leading AI labs, DeepSeek publishes the weights of its main models, usually under licenses that allow commercial use, together with technical reports that describe how they were trained. Open weights mean anyone can download a model, run it on their own hardware, fine-tune it for a specific task or offer it through their own service.

This has practical consequences. Organizations that cannot send data to an outside service can run a DeepSeek model inside their own infrastructure, and many cloud providers and AI platforms host DeepSeek models on servers in other countries. DeepSeek also released smaller distilled models, trained to imitate the reasoning of the large one, which can run on a powerful desktop computer through local tools such as Ollama or LM Studio.

Keep expectations realistic. The full-size models need serious server hardware, and the small distilled versions are noticeably less capable than the hosted assistant. Read the license of the specific model you plan to use as well, because terms can differ between releases.

DeepSeek's strongest areas are mathematics, programming and structured reasoning. In deep-thinking mode it handles multi-step problems, debugging, explaining algorithms and checking logic well, and seeing the reasoning laid out can help you learn the method as well as the answer. It is particularly strong in Chinese and English and copes with many other languages.

For everyday writing, summarizing and brainstorming it is a capable general assistant. Because the chat is free to use and the API has a reputation for being affordable, it has become popular with students, hobbyist developers and startups that want to experiment on a small budget.

Its limitations are those of any language model, plus a few of its own. It can still make factual mistakes and invent details, so verify important claims. The service has at times been slow or unavailable during periods of heavy demand. Some features that other assistants offer, such as image generation or voice conversations, may be missing. And like every hosted assistant it applies content policies, which reflect the regulations of the country where it operates, so some subjects may be answered cautiously or declined.

Before using any AI assistant, read its privacy policy, and DeepSeek is no exception. According to its policy, information collected through the hosted service, including your prompts, uploaded files and chat history, is stored on servers in the People's Republic of China and handled under the laws that apply there. Like other providers, it may use conversations to improve its services.

A number of companies, universities and public bodies have restricted the use of DeepSeek on work devices, and data protection regulators in some countries have examined how the service handles personal data. If you want to use it for work, check your organization's policy first. For personal use, the usual rules for any assistant apply: do not paste passwords, identity documents, financial details, health information or confidential business material.

If data location is a concern but you want DeepSeek's capabilities, the open-weight models offer an alternative: run a model locally, or use a provider that hosts it in a region and under terms you are comfortable with. In that case your prompts go to that provider rather than to DeepSeek, so review that provider's policy instead.

The official ways to use the assistant are the DeepSeek website and the official apps in the App Store and Google Play. Check that the developer name matches the company before installing, because popular AI tools attract copycat apps. Availability in app stores has varied by country at times, so the app may not be listed everywhere.

You can sign up with an email address and, depending on your region, with a phone number or a Google account. Protect the account like any other: use a unique password, keep your recovery options up to date and log out of shared computers. Follow DeepSeek's terms of use, which set out what the service may and may not be used for. rStock is not affiliated with DeepSeek.

To get good results, write clear and specific prompts with context, switch on deep-thinking mode for math, code and planning, and turn on search when you need current information. The visible reasoning is a useful learning aid, but judge the final answer on its own merits.

DeepSeek is best seen as one strong option among several. ChatGPT offers a broader set of built-in tools, such as image generation, voice conversations and agent features, with paid plans for heavier use. Search-focused tools such as Perplexity put cited web answers first. DeepSeek stands out for its reasoning ability, its free chat, its developer-friendly API and its openly published models.

Many people use more than one assistant: DeepSeek for math and code, another for research with sources or for multimedia tasks. Whichever you choose, the basics stay the same: protect your data, check important answers and pick the tool whose strengths and privacy terms suit the job.