DeepSeek Complete Guide: How to Use a High-Performance Free AI

DeepSeek is a high-performance large language model developed by a Chinese AI company, and it has attracted global attention largely because it's free to use. This guide covers DeepSeek's features, how to use it, how it compares to ChatGPT, and the precautions to keep in mind.

What Is DeepSeek?

DeepSeek is a large language model (LLM) developed by DeepSeek, a company headquartered in Hangzhou, China. The release of DeepSeek-V3 in late 2024 and DeepSeek-R1 in early 2025 sent shockwaves through the global AI industry with their combination of high capability and extremely low cost.

Key Models

• DeepSeek-V3: A general-purpose chat model. Uses a Mixture of Experts (MoE) architecture with 671 billion parameters.
• DeepSeek-R1: A reasoning-focused model. Especially strong at math, programming, and logical reasoning.
• DeepSeek Coder: A coding-specialized model.

Features

1. Free to Use

The most notable feature is completely free access via the web app (chat.deepseek.com). The message limit is relatively generous, making it sufficient for everyday use.

2. High Performance

DeepSeek scores on par with GPT-4o and Claude 3.5 Sonnet on major benchmarks. DeepSeek-R1 in particular delivers performance close to OpenAI o1 on math and coding reasoning tasks.

3. Dramatically Lower Cost

API pricing is roughly one-tenth or less of competitors. The reported training cost of around $6 million is remarkable compared to the billions spent by other leading models.

4. Open Source

The model weights are publicly available for anyone to download, customize, and deploy. Commercial use is permitted under the MIT license.

How to Use DeepSeek

Web App (Easiest)

1. Go to chat.deepseek.com 2. Sign up with your email or Google account 3. Type your message in the chat interface 4. Switch to "DeepThink (R1)" mode to activate reasoning mode

API Access

Developers can integrate DeepSeek into their own applications via API.

• API endpoint: api.deepseek.com
• Pricing:

- DeepSeek-V3: $0.27 input / $1.10 output per million tokens - DeepSeek-R1: $0.55 input / $2.19 output per million tokens

• Compatibility: OpenAI API-compatible format, making migration easy

Running Locally

Because DeepSeek is open source, you can run it on your own PC or server.

• Ollama: Run `ollama run deepseek-r1` to get started
• LM Studio: Download and run models through a graphical UI
• Requirements: The quantized version (7B/8B) runs on approximately 16GB of RAM

Comparison with ChatGPT

Where DeepSeek Wins

• Cost: Free or drastically cheaper API
• Math and logical reasoning: R1 has exceptional problem-solving ability
• Coding: Strong at implementing complex algorithms and debugging
• Open source: Local execution means no data ever leaves your machine

Where ChatGPT Wins

• Natural Japanese: ChatGPT is clearly superior for Japanese conversation and creative writing
• Multimodal: Rich image generation, recognition, and voice features
• Ecosystem: Extensive plugins, GPTs, and API integrations
• Reliability: More stable uptime and response speeds

Japanese Language Performance

DeepSeek's Japanese is adequate for practical tasks like drafting business emails, summarizing content, and translation. However, keep these considerations in mind:

Strong Areas

• Programming Q&A (code is language-agnostic)
• Technical document summarization
• Math and data analysis
• English ↔ Japanese translation assistance

Weaker Areas

• Questions about uniquely Japanese culture or customs
• Business writing requiring nuanced levels of politeness
• Local Japanese information (place names, company names, etc.)
• Creative Japanese writing (fiction, poetry, etc.)

Security Considerations

1. How Your Data Is Handled

DeepSeek's terms of service indicate that input data may be stored on servers in China. Keep these points in mind:

• Never input confidential information: Never enter internal documents, personal data, or passwords
• Check corporate policy: Your company's security policy may prohibit or restrict its use
• Alternative: Consider local execution when security is a concern

2. Chinese Regulatory Constraints

Under Chinese law, responses to certain politically sensitive topics (Tiananmen Square, Taiwan, etc.) may be restricted.

3. Local Execution as a Solution

If you want to ensure no data leaves your machine, running locally with Ollama or LM Studio is the best solution.

Recommended Use Cases

Best Uses

1. Learning to code: Get GPT-4 level coding assistance for free 2. Math and science problem solving: R1's reasoning capability is top-tier 3. English language learning: Great for proofreading and grammar explanations 4. API prototyping: Build AI application prototypes at minimal cost 5. Building a local AI environment: Privacy-first AI usage

Uses to Avoid

1. Handling confidential information: Carries security risk 2. Japanese creative writing: ChatGPT or Claude is more appropriate 3. Latest Japanese news and information: Be aware of the training data cutoff 4. Standalone production deployment: Stability lags behind OpenAI and Anthropic

Local Setup Guide

Quick Setup with Ollama

1. Install Ollama from ollama.com 2. Run in terminal:

• DeepSeek-R1 (reasoning model): `ollama run deepseek-r1:8b`
• DeepSeek-V3 equivalent: `ollama run deepseek-v3`

3. Chat begins in your terminal

GUI Setup with LM Studio

1. Install LM Studio from lmstudio.ai 2. Search for and download a DeepSeek model in the app 3. Start it as a local server 4. Use it as an OpenAI-compatible API from other applications

Frequently Asked Questions

Q: Is DeepSeek really safe to use?

A: When using the web app or API, your input data is sent to servers in China. Do not enter confidential information. For security-sensitive use cases, local execution is recommended.

Q: Does it support Japanese?

A: Yes. For practical tasks like summarization, translation, and Q&A, the quality is sufficient. However, it is somewhat less natural-sounding in Japanese compared to ChatGPT.

Q: Can I use it commercially?

A: The open-source version is available under the MIT license for commercial use. Commercial use via API is also permitted within the terms of service.

Q: Can it replace ChatGPT?

A: It depends on your use case. For math and coding, it matches or exceeds ChatGPT. For Japanese creative writing and multimodal tasks, ChatGPT has the edge. Using both together is recommended.

Conclusion

DeepSeek is a standout tool as a free, high-performance AI — particularly for programming and mathematics. That said, security considerations are non-negotiable. A smart approach is to use the web app for casual questions and coding assistance, and switch to local execution for sensitive work. Combining DeepSeek with ChatGPT or Claude lets you get the best out of each.