How to Use DeepSeek: Web, App, DeepThink and Search

DeepSeek is an AI chat assistant made by Hangzhou DeepSeek Artificial Intelligence Co., Ltd., a company registered in China. It works much like ChatGPT: you type, it answers, and you can keep the conversation going. Plenty of people use it for reasoning, writing and coding. Before you pour your business into it, though, there are a few things in its own terms and privacy policy you should know. I've put those near the end.

Step 1: Choose web, app or API

Option	Where to find it	Best for
DeepSeek Web	Chat with DeepSeek on deepseek.com	Everyday chat on a laptop
DeepSeek app	Get App on deepseek.com (QR code), or your phone's app store	Chat on the go
API Platform	API Platform and API Docs on deepseek.com	Developers building DeepSeek into their own tools

DeepSeek's homepage also lists a desktop tool called DeepSeek Harness. If you just want to chat, the web version is the quickest start.

Step 2: Sign up

Create an account with your email address or phone number and a password. DeepSeek's terms say the service is primarily intended for adults. If you're under 18, or under the minimum age in your country, the terms say you should read them with a parent or guardian and only use DeepSeek with their consent.

Step 3: Ask your first question

Type into the message box and press Enter. DeepSeek reads text, images and files you give it, and it can answer with text, tables and code. Give it the task, the context and the format you want back, the same way you would brief a person.

Copy this prompt

I run a small online candle shop. Write five product descriptions for soy candles in these scents: fig, sea salt, cedar, vanilla and orange. Keep each under 60 words, warm and plain, and end each one with a suggestion of where to put the candle at home.

If you want more starting points, my list of DeepSeek prompts covers marketing, writing and research tasks you can copy.

Step 4: Turn on DeepThink or Search

Under the message box you'll see two buttons, DeepThink and Search. They change how DeepSeek answers.

• DeepThink: switch it on for maths, logic, planning or code, where you want DeepSeek to reason through the problem step by step before it answers. It's slower, so leave it off for simple questions.
• Search: switch it on when the answer depends on recent information, like news, prices or anything that changes. DeepSeek's own terms say Search may improve accuracy to some extent, but that inaccuracy in AI answers can't be entirely avoided.

My rule: use Search for facts, DeepThink for problems, and both when you need a reasoned answer about something current.

Step 5: Upload files and images

You can attach documents and images to a chat and ask DeepSeek to summarise, compare or pull details out of them. It's useful for reading a long contract, comparing two quotes or turning a screenshot of a table into text. Check the result against the original, because the terms are clear that you're responsible for any decision you make based on an answer.

Step 6: Manage your chat history

Your conversations are saved in the sidebar so you can go back to them. DeepSeek's privacy policy says you can copy or delete your chat history in settings. If you delete your account, it says you won't be able to reactivate it or get any of that content back.

Another Chinese model with a free chat app is covered in my guide to whether Qwen is free.

Common mistakes to avoid

• Leaving Search off when you ask about something recent, then trusting an out-of-date answer.
• Leaving DeepThink on for quick questions, which only makes you wait longer.
• Pasting a whole messy document with no instruction. Tell it what you want from the file first.
• Copying an answer straight into a published post without checking it and labelling it as AI-generated.

Using DeepSeek in your own tools

Developers can get an API key from the DeepSeek API Platform. The API docs say it uses the OpenAI API format, so code written for OpenAI often works with a change of address and model name. As of October 2026, the docs say the deepseek-flash model name is served by DeepSeek-V4.1-Flash-1017, and that tools such as Claude Code, GitHub Copilot and OpenCode can use DeepSeek as the backend model directly.

What to know before you use DeepSeek for work

These come straight from DeepSeek's own policies, and they're the details most guides leave out.

• Where your data goes: the privacy policy says DeepSeek directly collects, processes and stores your personal data in the People's Republic of China.
• What it collects: your prompts, voice input, uploaded files, photos, feedback and chat history.
• Training: the policy says your data is used to train and improve its models, and it lists a right to opt out of that.
• Publishing outputs: the terms say that if you publish something DeepSeek wrote, you must check it's accurate and clearly label it as AI-generated.

That last point matters for anyone using it for blog posts or social media. Most people don't realise the terms ask for an AI label on published content.

My advice

DeepSeek is a capable free assistant for brainstorming, coding and working through problems. Keep anything confidential, like client data, financial records or unreleased plans, out of it, given where the data is stored. If that's a deal-breaker for your business, my guide to DeepSeek alternatives lists other assistants you can try instead.

Frequently asked questions

Is DeepSeek free to use?

You can chat with DeepSeek on the web and in the app after signing up. The API is a separate, paid service for developers, with its own pricing page.

What does DeepThink do in DeepSeek?

DeepThink makes DeepSeek reason through a problem before answering. It's best for maths, logic, planning and code, and slower than a normal reply.

Where does DeepSeek store my data?

DeepSeek's privacy policy says it directly collects, processes and stores personal data in the People's Republic of China.

Can I use DeepSeek answers in my blog posts?

Its terms say that if you publish outputs, you must check they're accurate and clearly indicate the content was generated by AI.

Can under-18s use DeepSeek?

DeepSeek says the service is primarily intended for adults. Under-18s should read the terms with a legal guardian and use it only with their consent.