In early 2025, DeepSeek suddenly appeared on everyone’s radar, briefly topping the global App Store download charts and sending Nvidia’s US stock price down by nearly 17%. If you didn’t understand what it was back then, you likely never used it seriously—once the hype died down, many people put it aside. But as an AI tool, DeepSeek is worth understanding not for its fleeting popularity, but for its actual capabilities.
This article aims to clarify: what DeepSeek can actually do, how it differs from ChatGPT and other AIs, and when it’s best suited for use.
What Is DeepSeek?
DeepSeek is a large language model product developed by DeepSeek (DeepSeek), a company headquartered in Hangzhou and backed by the quantitative private equity firm High-Flyer Technologies (High-Flyer Technologies). DeepSeek stands out as somewhat of an outlier in the AI field—the team is relatively small, yet the model quality is exceptionally high. They have adopted an open-source strategy, publicly releasing model weights so that developers worldwide can download and use them.
There are currently two main product lines:
DeepSeek-V3: A general-purpose model for writing, Q&A, and analysis tasks, using a Mixture of Experts architecture with overall capabilities comparable to GPT-4o.
DeepSeek-R1: A reasoning-enhanced model optimized for tasks requiring "deep thinking," such as mathematics, logic, and coding. It incorporates a chain-of-thought mechanism similar to OpenAI’s o1, surpassing GPT-4 and Claude 3 Opus in certain reasoning tasks.
You can access it directly via chat.deepseek.com without complex registration or a credit card—it is completely free, a rarity among AI tools.
The Reason for Its Fame: Cost Efficiency
What shook the entire AI industry was not just DeepSeek’s capabilities, but its cost structure.
According to data released by DeepSeek, training the V3 model required only about $5.57 million in GPU compute power. Compared to the hundreds of millions of dollars spent by OpenAI and Anthropic, this figure isUnbelievable (unbelievably) low. While the authenticity of this number has been debated, the industry widely acknowledges that DeepSeek’s training efficiency far exceeds its peers.
The significance of this is that it proves high-performance models do not require insane compute spending, directly challenging the industry narrative that "more Nvidia GPUs are always better."
For ordinary users, this means you can access a GPT-4-level model for free—a feat that was previously impossible.
Core Capabilities
Mathematics and Reasoning
This is DeepSeek-R1’s standout feature.
In professional math benchmarks like AIME (American Invitational Mathematics Examination) and MATH, DeepSeek-R1 achieved scores comparable to OpenAI’s o1, surpassing GPT-4o and Claude 3.5 Sonnet. For solving equations, proving theorems, and handling probability/statistics problems, its logical clarity is high.
Its reasoning style can be described as "think slowly, think clearly, then speak." Before answering, R1 displays a "thinking process" (labeled Think), showing the reasoning chain step-by-step so you can see how it reaches its conclusion. This transparency allows you to verify its logic, but it also means longer response times—you’ll need to wait a bit.
Coding
DeepSeek’s performance in code generation is the best among domestic models, placing it on par with GPT-4o and even stronger in tasks for certain languages.
It covers common languages well: Python, JavaScript, TypeScript, Java, Go, C++. It can help you write functions, debug errors, refactor code, explain logic, and add comments. For backend developers handling algorithmic problems and logic-intensive tasks, the R1 model is particularly useful because it analyzes step-by-step rather than jumping straight to a conclusion.
Chinese Understanding and Generation
As a model developed by a domestic team, DeepSeek’s Chinese understanding and generation are naturally robust. It accurately understands ambiguous Chinese expressions, and its generated Chinese is fluent and natural, unlike some models that suffer from heavy "translationese."
It handles Chinese documents, writing assistance, and administrative official documents well, without spitting out excessive filler content.
Long-Text Processing
DeepSeek-V3 supports a 64K context window, capable of handling quite long documents. Feeding in a complete contract, report, or code file to ask questions is entirely feasible. While not as large as Claude’s 200K, it is more than sufficient for daily use.
Comparison with Other AI Tools
vs ChatGPT:
In terms of pricing, DeepSeek is completely free, while ChatGPT has usage limits and requires payment for full features.
In terms of capability, the combination of V3’s dialogue and R1’s reasoning can compete directly with GPT-4o in mathematics, coding, and logical reasoning, sometimes even outperforming it. However, ChatGPT’s ecosystem (GPTs, plugins, DALL-E, voice, web browsing) is more complete, and its multimodal capabilities are more mature.
In terms of Chinese experience, DeepSeek’s Chinese is more idiomatic, whereas ChatGPT can sometimes feel overly translated.
vs Claude:
In reasoning tasks, DeepSeek R1 and Claude 3.5 Sonnet trade wins; both are top-tier. In writing style, Claude’s language is more natural and fluid, while DeepSeek is slightly more "rigid" but still good. Regarding context length, Claude supports 200K, while DeepSeek V3 supports 64K—a noticeable gap.
vs Domestic Products (Kimi, ERNIE Bot, Tongyi Qianwen, etc.):
DeepSeek’s mathematics and coding capabilities are significantly ahead among domestic models. ERNIE Bot and Tongyi Qianwen have stricter content safety reviews; DeepSeek is slightly more open on some topics (though it still has content restrictions and is not without censorship). Kimi has specialized optimizations for long-text processing, making it competitive in the specific scenario of document handling.
Who Should Use DeepSeek?
Students and Researchers: For math problems, derivation processes, and physics/chemistry questions, R1’s chain-of-thought reasoning is very helpful for learning—it gives you not just the answer, but the process.
Developers: For coding issues, algorithmic problems, and debugging, it is free, powerful, and offers extremely high cost-performance value.
Users Who Need High-Frequency AI Access Without Paying: The free version has almost no functional limits (with some queuing during peak hours), making it one of the strongest alternatives to ChatGPT’s free tier.
Chinese Writing Scenarios: For official documents, reports, and copywriting, DeepSeek’s Chinese output quality is good, and you don’t have to worry about usage quotas.
Practical Usage Tips
Choose the R1 model for deep reasoning. The platform defaults to V3; switching to R1 requires manual selection. For math problems, logical reasoning, and complex coding issues—R1 is clearly more stable, though slower. That "thinking process" is often highly valuable.
Look at its thinking process, not just the conclusion. R1’s thinking section displays its reasoning chain. If you doubt the conclusion, check where the thinking process went wrong; you’ll often find which assumption was flawed.
Use V3 for daily conversation and writing. V3 is fast and sufficient for most scenarios; there’s no need to use R1 every time.
Don’t ask for real-time information. DeepSeek does not have web-browsing capabilities (by default); it doesn’t know what happened today, so don’t use it as a search engine.
Describe complex tasks directly in Chinese. No need to force yourself to use English—its Chinese understanding has no obvious weaknesses. Clear descriptions in Chinese usually yield excellent results.
Important Notes
Content Restrictions Apply. DeepSeek still has content filtering mechanisms; it will refuse to answer or provide official stances on politically sensitive topics.
Queuing During Peak Hours. Being free and popular, you may occasionally encounter wait times during daytime working hours. If you’re in a hurry, use it during off-peak hours or access it via the API.
Data Privacy. As with all online AI services, do not input company secrets or personal sensitive information.
API and Developer Usage
DeepSeek offers API access at extremely low prices—roughly one-tenth or even less of GPT-4o’s cost—while delivering comparable model quality. Many developers and startup teams have already adopted the DeepSeek API as a cost-effective alternative to OpenAI’s API, achieving significant savings.
Additionally, DeepSeek has open-sourced its model weights, which are available for download on Hugging Face. Teams with the infrastructure to deploy models locally can operate entirely independently of cloud services, maintaining full control over their data—a valuable advantage for enterprise users navigating compliance requirements.
Summary
DeepSeek is a genuinely outstanding AI tool, not driven by hype but by tangible capability. Its combination of free access, strong Chinese language support, and robust math and coding performance has no direct equivalent in the current market.
If you haven’t yet given it a serious try, we recommend visiting chat.deepseek.com to test it on a real reasoning task—ask it to solve a moderately challenging math problem or have its R1 model analyze a segment of code logic, observing its “thinking process.” You’ll likely find that it performs far better than you might expect.