Learn how to use DeepSeek Chat on web and mobile, write better prompts, handle files safely, and make a current DeepSeek V4 API request. Last verified: July 28, 2026.
DeepSeek Chat is an AI chatbot you can use for writing, coding, summarizing, brainstorming, learning, and analyzing information. The easiest way to use it is to open the official DeepSeek Chat website or install the official mobile app, type a clear prompt, review the answer, and keep refining your request until the output is useful.
This guide shows you how to use DeepSeek Chat safely and effectively on the web, on mobile, with files, with better prompts, and through the DeepSeek API if you are a developer.
Quick Answer: How to Use DeepSeek Chat
To use DeepSeek Chat:
- Go to the official DeepSeek website or official chat page.
- Sign in or create an account if the interface asks you to.
- Start a new chat.
- Type a specific prompt, not a vague question.
- Add context, examples, format requirements, or files when needed.
- Read the answer critically.
- Ask follow-up questions to improve the result.
- Verify important facts before using the answer in work, school, finance, health, legal, or technical decisions.
DeepSeek’s official homepage points users to free chat access and to its API platform for developers. The official chat page describes DeepSeek Chat as an assistant for coding, content creation, file reading, document uploads, and long-context conversations.
What Is DeepSeek Chat?
DeepSeek Chat is the user-facing chatbot interface from DeepSeek. Instead of writing code or calling an API, you interact with it through normal conversation: ask a question, give a task, upload or paste information if the feature is available, and refine the result through follow-up prompts.
For most users, DeepSeek Chat is best for:
| Task | Example |
|---|---|
| Writing | Draft emails, outlines, social posts, product descriptions, or blog sections |
| Summarizing | Turn long notes, articles, or documents into concise summaries |
| Coding | Explain errors, review code snippets, generate examples, or compare approaches |
| Learning | Break down difficult concepts into beginner-friendly explanations |
| Brainstorming | Generate ideas, names, angles, outlines, or checklists |
| Analysis | Compare options, organize information, or extract key points |
DeepSeek Chat, the DeepSeek mobile app, the DeepSeek API, and Chat-Deep.ai’s independent browser chat are different access paths. Developers building software should use the official API documentation and the current model IDs deepseek-v4-flash or deepseek-v4-pro. The old deepseek-chat and deepseek-reasoner cutoff announced for July 24 has passed; do not copy those names into new API examples.
Use Only Official DeepSeek Access Points
Before using DeepSeek Chat, make sure you are using an official entry point. AI tools often have lookalike apps, copied websites, and unofficial wrappers that may not follow the same privacy, security, or reliability standards.
| Access Method | Best For | What to Check |
|---|---|---|
| Official DeepSeek website | Finding the correct chat, API, and app links | Use the official DeepSeek homepage |
| DeepSeek Chat | Everyday AI chat, writing, coding, summarizing, and file tasks | Make sure you are on the official chat service |
| iOS app | iPhone and iPad users | Check the App Store listing and developer identity |
| Android app | Android users | Check the Google Play listing and developer identity |
| API docs/platform | Developers | Use the official API docs and platform |
| Status page | Outages and “server busy” issues | Check the official service status page |
The official Apple App Store listing describes “DeepSeek – AI Assistant” as DeepSeek’s official AI assistant, and Google Play lists the official Android app under the package for DeepSeek Chat. DeepSeek also provides an official app download page that points users to Google Play and iOS download methods.
How to Use DeepSeek Chat on the Web
The web version is the simplest way to start.
1. Open the Official Chat Page
Start from the official DeepSeek website, then choose the chat option, or go directly to the official chat service. The homepage currently highlights free access to DeepSeek and also links to API access for developers.
2. Sign In If Required
DeepSeek may ask you to sign in, create an account, or verify access depending on your region, device, account status, or current service conditions. Access rules can change, so follow the instructions shown on the official page.
3. Start With a Clear First Prompt
A weak prompt gives you a generic answer. A strong prompt gives DeepSeek a role, task, context, constraints, and output format.
Weak prompt:
Write about productivity.
Better prompt:
Act as a productivity coach. Create a 7-day productivity plan for a remote software developer who gets distracted by meetings and Slack. Include daily actions, time blocks, and a short evening review checklist.
4. Refine the Answer With Follow-Up Prompts
Do not expect the first response to be perfect. Treat DeepSeek Chat like a working draft assistant.
Useful follow-ups include:
- “Make this more concise.”
- “Turn this into a step-by-step checklist.”
- “Give me three alternative versions.”
- “Explain this for a beginner.”
- “Add examples.”
- “Challenge your previous answer and identify weak points.”
- “Rewrite this for a professional audience.”
- “Format the answer as a table.”
5. Verify Before You Use the Output
DeepSeek’s own privacy policy includes a caution that AI-generated outputs may not always be factually accurate and should not be relied on without verification. Use DeepSeek to speed up thinking and drafting, but verify important facts from primary sources.
How to Use DeepSeek Chat on Mobile
DeepSeek’s mobile app is useful when you want quick answers, drafts, summaries, or coding help from your phone.
On iPhone or iPad
- Open the Apple App Store.
- Search for “DeepSeek – AI Assistant.”
- Check that it is the official DeepSeek listing.
- Install the app.
- Open it and sign in if prompted.
- Start a chat and ask your question.
The App Store listing describes the app as DeepSeek’s official AI assistant and says it is powered by DeepSeek’s latest flagship model.
On Android
- Open Google Play.
- Search for “DeepSeek – AI Assistant.”
- Check that the developer/listing is official.
- Install the app.
- Open it and sign in if prompted.
- Start with a specific prompt.
Google Play lists the DeepSeek app as an official AI assistant and shows it under the Productivity category.
The Best Way to Prompt DeepSeek Chat
Use this simple formula:
Role + Task + Context + Requirements + Output Format
Here is what each part does:
| Prompt Part | What It Means | Example |
|---|---|---|
| Role | Who DeepSeek should act as | “Act as a senior Python tutor” |
| Task | What you want done | “Explain decorators” |
| Context | Background information | “I understand functions but not closures” |
| Requirements | Rules or constraints | “Use simple examples and avoid jargon” |
| Output format | How the answer should look | “End with a quiz and answer key” |
Copy-and-Use DeepSeek Prompt Examples
| Goal | Prompt |
|---|---|
| Learn a topic | “Explain [topic] to a beginner. Start with a plain-English definition, then give an analogy, then show a practical example.” |
| Summarize text | “Summarize the text below in 5 bullet points. Then list the main action items and any unclear assumptions.” |
| Improve writing | “Rewrite this paragraph to sound more professional and concise. Keep the meaning, remove repetition, and explain the edits briefly.” |
| Write code | “Act as a senior [language] developer. Write a function that [task]. Include comments, edge cases, and a short explanation.” |
| Debug code | “Find the bug in this code. Explain the likely cause, show the corrected version, and suggest how to prevent this issue.” |
| Compare options | “Compare [option A] and [option B] for [use case]. Use a table with pros, cons, risks, cost factors, and best-fit scenarios.” |
| Research planning | “Create a research plan for [topic]. Include search terms, primary sources to check, questions to answer, and warning signs of unreliable sources.” |
| Decision-making | “Help me decide whether to [decision]. Ask any missing questions first, then create a decision matrix with trade-offs.” |
Practical Ways to Use DeepSeek Chat
Use DeepSeek for Writing
DeepSeek can help you write faster, but it works best when you give it a clear target audience, tone, and purpose.
Example:
Write a cold email to a SaaS operations manager. The goal is to book a demo for a workflow automation tool. Keep it under 120 words, make it specific, avoid hype, and include one clear call to action.
You can then refine with:
Make it warmer and less salesy.
Or:
Give me three subject lines and explain which one is most likely to get opened.
Use DeepSeek for Coding
DeepSeek Chat can explain code, generate examples, debug errors, and compare technical approaches. For coding tasks, provide:
- the programming language
- the framework or version
- the exact error message
- the relevant code snippet
- what you expected to happen
- what actually happened
Example:
Act as a senior React developer. I’m getting this error: [paste error]. Here is the component: [paste code]. Explain the cause, fix the code, and show a cleaner version using best practices.
For production code, still review the result manually and run tests. AI-generated code can be incomplete, insecure, outdated, or incompatible with your environment.
Use DeepSeek for Summarizing
For summaries, tell DeepSeek what to preserve and what to ignore.
Example:
Summarize this meeting transcript for an executive. Include decisions, owners, deadlines, risks, and unresolved questions. Ignore small talk.
This is more useful than simply saying:
Summarize this.
Use DeepSeek for Research Support
DeepSeek can help organize research, generate questions, create comparison tables, and identify what you still need to verify. It should not be your only source for current facts.
Example:
I’m researching [topic]. Create a fact-checking plan. List the claims I need to verify, the best primary sources to check, and the questions I should answer before publishing.
Use DeepSeek for Learning
DeepSeek is helpful when you ask it to adapt to your level.
Example:
Teach me SQL joins. Assume I know basic SELECT statements but not joins. Use a small table example and give me 5 practice questions.
Then continue with:
Quiz me one question at a time and wait for my answer.
How to Use Files and Long Documents in DeepSeek Chat
The official chat page describes DeepSeek Chat as supporting file reading, document uploads, and long-context conversations. If the upload option is available in your account or current interface, you can use it for tasks such as summarizing PDFs, extracting action items, comparing documents, or asking questions about notes.
A good file prompt looks like this:
Read the uploaded document. Create a concise summary, then extract key dates, names, risks, and action items. If the document does not contain enough information to answer something, say “Not stated in the document.”
For better results:
- Tell DeepSeek what the document is.
- Say what you want extracted.
- Specify the output format.
- Ask it to separate facts from assumptions.
- Check important details manually in the original file.
Do not upload confidential, sensitive, legal, medical, financial, customer, employee, government, or proprietary documents unless you have reviewed DeepSeek’s privacy policy and your organization’s AI rules.
Privacy and Safety: Match the Rules to the Way You Access DeepSeek
Before entering text or uploading a file, identify the service you are actually using. Official DeepSeek Chat, the official mobile app, a downstream API application, a third-party model host, and a self-hosted model do not necessarily have the same controller, data flow, storage location, logs, retention, or security controls.
Official DeepSeek Chat and app
The DeepSeek Privacy Policy applies to official services that link to or reference it. It says DeepSeek may collect account data, text and voice input, prompts, uploaded files, photos, feedback, chat history, device and network information, IP address, cookies, logs, and approximate location.
The policy says the covered services are not designed or intended to process sensitive personal data and advises users not to provide it. It also says collected personal data is directly processed and stored in the People’s Republic of China.
DeepSeek API applications and third-party interfaces
DeepSeek’s official-service policy expressly excludes processing rules for personal data collected from end users inside downstream applications developed through the Open Platform. Under the Open Platform Terms, the application operator controls that end-user processing and must provide an appropriate privacy disclosure, establish a legal basis, and implement organizational and technical safeguards.
The exclusion is not a universal no-processing or zero-retention promise for the DeepSeek API. A developer should assess the platform terms, account information, settings, caching, request and application logs, retention, hosting architecture, support access, subprocessors, and any written contract.
If another website, browser extension, workplace tool, cloud marketplace, or mobile app provides access to a DeepSeek model, review that operator’s identity and privacy notice. Do not assume it is operated by DeepSeek or that the official Chat policy describes its complete data flow.
Self-hosted DeepSeek models
Using DeepSeek model weights does not by itself establish that prompts are sent to DeepSeek, but the deploying organization becomes responsible for infrastructure, access, encryption, logs, backups, retention, monitoring, updates, connected tools, and incident response. Verify every supporting service rather than treating “self-hosted” as an automatic privacy guarantee.
Avoid entering this type of data
- Passwords, API keys, access tokens, recovery codes, or private keys.
- Customer records, employee files, or other private user data.
- Medical, legal, financial, tax, payment, or other regulated information.
- Unpublished business strategy, trade secrets, or restricted source code.
- Government, school, or workplace information you are not authorized to disclose.
- Personal information about children or vulnerable individuals.
Regulatory context
South Korea suspended new downloads of the official DeepSeek app in February 2025 while its privacy practices were examined. The app became available for download again in April 2025 after DeepSeek revised its privacy disclosures and reflected at least some of the regulator’s recommendations.
That event concerned the official app and its South Korean distribution and data practices. It should not be presented as proof that every downstream API application, third-party-hosted model, or self-hosted deployment follows the same data path.
For regulated or confidential work, use only a product and deployment approved after reviewing the complete data flow, controller and provider responsibilities, contract, region, logs, caching, retention, subprocessors, access controls, and deletion process.
DeepSeek Chat vs DeepSeek API
Most people should start with DeepSeek Chat. Developers should use the API when they need to connect DeepSeek to software, automations, agents, internal tools, or production workflows.
| Feature | DeepSeek Chat | DeepSeek API |
|---|---|---|
| Best for | Normal users | Developers and technical teams |
| Interface | Web or mobile chat | Code/API requests |
| Setup | Simple | Requires API key and implementation |
| Billing | Chat access may be free or subject to current platform rules | Usage-based token pricing |
| Control | Limited to chat interface | More control over model, requests, and integration |
| Privacy responsibility | The official Privacy Policy governs DeepSeek Chat and other covered official services. | The downstream application operator controls its end-user processing; DeepSeek-side API processing must be assessed separately under the Open Platform terms, settings, architecture, logs, retention, and contract. |
| Good for | Writing, learning, coding help, summaries | Apps, agents, backend workflows, automation |
The official API docs say DeepSeek’s API is compatible with OpenAI and Anthropic-style API formats by changing configuration. The same docs list the OpenAI-format base URL, Anthropic-format base URL, API key requirement, and current model IDs.
Current DeepSeek API Models and Pricing
As of the last verification date for this article, DeepSeek’s official pricing page lists deepseek-v4-flash and deepseek-v4-pro, both with 1M context length and a maximum output of 384K. It lists per-1M-token prices for cache hits, cache misses, and output tokens, and notes that prices may vary and should be checked on the official pricing page.
| API Model | Best For | Official Pricing Snapshot |
|---|---|---|
deepseek-v4-flash | Faster, lower-cost workloads | Cache hit: $0.0028 / 1M input tokens; cache miss: $0.14 / 1M input tokens; output: $0.28 / 1M tokens |
deepseek-v4-pro | More demanding reasoning and complex tasks | Cache hit: $0.003625 / 1M input tokens; cache miss: $0.435 / 1M input tokens; output: $0.87 / 1M tokens |
Always check the official pricing page before building cost estimates, because DeepSeek states that product prices may vary.
Basic DeepSeek API Example
Use the API only if you are comfortable working with environment variables, HTTP requests, and API keys. Never expose your API key in frontend code, public repositories, screenshots, or client-side apps.
export DEEPSEEK_API_KEY="your_api_key_here"
curl -sS https://api.deepseek.com/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer $DEEPSEEK_API_KEY" \
-d '{
"model": "deepseek-v4-flash",
"messages": [
{
"role": "user",
"content": "Explain recursion in simple terms and give one short example."
}
],
"thinking": {"type": "disabled"},
"max_tokens": 512,
"stream": false
}'The official docs include example API calls and show that stream can be set to true for streaming responses.
Common DeepSeek Chat Problems and Fixes
| Problem | What It Usually Means | What to Try |
|---|---|---|
| DeepSeek says “server busy” | The service may be overloaded or temporarily degraded | Wait, refresh, try again later, or check the official status page |
| The page will not load | Browser, network, regional, or service issue | Try another browser, clear cache, disable extensions, or check status |
| Login does not work | Account, region, authentication, or temporary service issue | Retry later, check email/phone login details, or use another official login method if available |
| File upload is missing | Feature availability may vary by interface, mode, account, or region | Try web instead of mobile, start a new chat, or use paste/text instead |
| The answer is wrong | AI outputs can be inaccurate | Ask for sources, verify manually, and check primary references |
| The answer is too generic | The prompt lacks context | Add audience, goal, constraints, examples, and output format |
| API call fails | Wrong key, model name, endpoint, billing, request body, or deprecation issue | Check the current API docs, model names, and account balance |
The official status page showed “Everything is running smoothly” and listed Web Chat Service and API Service uptime for April–July 2026 at the time checked. If you experience errors, check the status page before assuming the problem is your device.
DeepSeek Prompting Tips for Better Results
Give DeepSeek a Specific Job
Instead of:
Help me with marketing.
Use:
Act as a B2B SaaS marketing strategist. Create a landing page outline for a workflow automation tool targeting operations managers at companies with 50–500 employees.
Add Constraints
Constraints make outputs more useful.
Example:
Keep the answer under 300 words. Use plain English. Avoid hype. Include one example and one common mistake.
Ask for a Format
If you need something usable, specify the format.
Example:
Return the answer as a table with columns for task, priority, estimated time, owner, and next step.
Ask DeepSeek to Explain Its Assumptions
Example:
Before answering, list the assumptions you are making. Then give the answer. If an assumption is uncertain, mark it as uncertain.
Ask for a Second Pass
A strong workflow is:
- Generate the first draft.
- Ask DeepSeek to critique it.
- Ask for a revised version.
- Review it yourself.
Example:
Critique your previous answer. Identify missing details, weak reasoning, and any claims that should be verified. Then rewrite it more accurately.
What DeepSeek Chat Is Good At — and What to Be Careful With
| Good Use | Use With Caution |
|---|---|
| Drafting and rewriting | Final legal, medical, or financial decisions |
| Explaining concepts | Current facts without verification |
| Generating code examples | Production code without testing |
| Summarizing non-sensitive text | Confidential document analysis |
| Brainstorming ideas | Claims about people, companies, laws, or prices |
| Comparing options | Security-sensitive or regulated workflows |
DeepSeek can save time, but it should not replace your judgment. For anything high-stakes, use it as a helper, not an authority.
Is DeepSeek Better Than ChatGPT?
Not universally. The better tool depends on what you need, where you live, your privacy requirements, your workflow, and whether you are using the chat interface or API.
DeepSeek may be attractive if you want a free or low-cost AI assistant, coding help, long-context tasks, or API access with competitive pricing. ChatGPT, Claude, Gemini, Perplexity, and other tools may be better depending on your need for integrations, enterprise controls, multimodal features, citations, privacy posture, or workplace approval.
A practical approach is to test the same task in two or three tools and compare:
- accuracy
- clarity
- speed
- cost
- privacy fit
- formatting quality
- ability to follow instructions
- suitability for your specific workflow
A Simple DeepSeek Chat Workflow for Beginners
Use this workflow for almost any task:
- Define the outcome
Say exactly what you want: an email, summary, plan, table, code snippet, or explanation. - Give context
Explain the audience, goal, background, constraints, and any source material. - Request a format
Ask for bullets, table, checklist, JSON, outline, or step-by-step instructions. - Review the first answer
Look for missing details, weak logic, unsupported claims, or factual errors. - Ask for improvements
Use follow-ups like “make it more specific,” “add examples,” or “remove repetition.” - Verify important information
Check primary sources before publishing, submitting, shipping, or acting on the result.
FAQ
Is DeepSeek Chat free?
DeepSeek’s official homepage currently says “Free access to DeepSeek” for the chat experience. The API is different: it is usage-based and billed by tokens according to the official API pricing page.
Do I need an account to use DeepSeek Chat?
Access requirements can change. The safest answer is to open the official chat page and follow the current sign-in or account instructions shown there.
Can DeepSeek Chat write code?
Yes. The official chat page describes DeepSeek Chat as an assistant for coding, among other tasks. For serious work, review the code, run tests, and check security-sensitive logic manually.
Can DeepSeek Chat read files?
The official chat page describes file reading and document upload support. Feature availability may vary by interface, account, region, or current product changes, so use the upload option only when it is visible in your current interface.
Is DeepSeek Chat safe to use?
It depends on the information and workflow. For official DeepSeek Chat, the official Privacy Policy describes collection of prompts, uploaded files, chat history, device and network information, and direct processing and storage in the People’s Republic of China. Use it for non-sensitive tasks and verify important outputs, but do not enter confidential, regulated, or sensitive data unless that exact use has been approved. API applications, third-party-hosted services, and self-hosted models require separate assessments.
What should I avoid entering into DeepSeek Chat?
Avoid passwords, API keys, private documents, customer data, financial records, medical information, legal files, confidential business information, and any data your school, employer, or client does not allow you to share with external AI tools.
Why is DeepSeek Chat saying “server busy”?
“Server busy” usually means temporary overload or service disruption. Wait and try again, or check the official DeepSeek status page. The status page reports current system status and historical uptime for the API and web chat service.
What is the difference between DeepSeek Chat and DeepSeek API?
DeepSeek Chat is the web or mobile chatbot for normal users. The API is for developers who want to connect DeepSeek models to apps, agents, automations, and software systems. The official API docs explain model names, base URLs, API keys, and sample API calls.
Which DeepSeek API model should I use?
For many developer workloads, start by testing deepseek-v4-flash because it is the lower-cost option. Use deepseek-v4-pro when the task requires stronger reasoning or more complex analysis. Check the official pricing and model details before choosing.
Are deepseek-chat and deepseek-reasoner still valid API model names?
Do not use them for new work. DeepSeek announced that both names would become inaccessible after July 24, 2026 at 15:59 UTC, and that date has passed. The current official model list shows deepseek-v4-flash and deepseek-v4-pro. Existing integrations should migrate to an explicit V4 ID and set thinking mode deliberately.