DeepSeek vs ChatGPT: Detailed AI Model Comparison

Nowadays, artificial intelligence (AI) has literally burst into everyday life. It has long since moved beyond simple things like solving math problems—now AI handles much more serious challenges, such as processing huge volumes of data or preparing analytical reports. 

In this article, we'll examine two AI models that have recently captured the artificial intelligence market: DeepSeek, created by the Chinese company DeepSeek AI, and ChatGPT, developed by the American company OpenAI.

What Are DeepSeek and ChatGPT?

DeepSeek is a free chatbot and artificial assistant created by the Chinese company DeepSeek AI in 2025. The development cost of DeepSeek also generated significant buzz in the media and social networks—it amounted to just $5.6 million. Moreover, DeepSeek's development used only 2048 NVIDIA chips. By February 2025, DeepSeek released several versions of its product—DeepSeek V3 and R1. Among their features were open-source code and free access, which significantly increased DeepSeek's popularity from the start. The DeepSeek model is oriented toward a wide range of tasks, including text generation, programming, and data analysis.

ChatGPT is an AI-powered chatbot created by OpenAI, founded in 2015 by Elon Musk and Sam Altman. It was first shown to the world in November 2022 and immediately caused a sensation in the AI field. ChatGPT is based on the GPT (Generative Pre-trained Transformer) architecture. By 2025, newer, more advanced versions were released, such as GPT-4o and o1. However, there are downsides—to access all its capabilities, you need a paid subscription, unlike the free DeepSeek.

Key Differences Between DeepSeek and ChatGPT

DeepSeek and ChatGPT have a number of fundamental differences.

The first difference is the distribution model. DeepSeek is positioned as an open platform: its source code is available on GitHub, and basic functions are provided free of charge through a web interface, API, and mobile applications. This makes it an ideal choice for developers wishing to integrate AI into their projects, or for users on a limited budget. ChatGPT uses a freemium model: the free version is limited in the number of requests and functionality, while full access to advanced models (such as GPT-4o) requires a subscription costing from $20 to $200 per month, depending on the plan.

The second difference is the architectural approach. DeepSeek uses Mixture of Experts (MoE) technology, where the model consists of many specialized subnetworks. This reduces computational costs and speeds up query processing. ChatGPT relies on the classic GPT architecture, which requires more resources but provides deep contextual understanding and high versatility.

Differences in Language Models

The technical foundation of DeepSeek and ChatGPT significantly affects their performance. ChatGPT is built on the GPT architecture, which is a transformer with a huge number of parameters. For example, GPT-4 has over a trillion parameters, and the latest versions, such as o1, reach 1.8 trillion. Training such models requires colossal resources.

DeepSeek uses a different architecture called MoE. In this system, the model consists of multiple "experts," each specializing in a specific type of task: one might handle programming, another text analysis, and a third mathematical calculations. According to DeepSeek AI, training version V3 cost only $5.58 million, which is tens of times cheaper than ChatGPT.

Another difference lies in the training methods used. ChatGPT uses hundreds of terabytes of data and the RLHF (Reinforcement Learning from Human Feedback) technique, which helps the model better understand user requirements and avoid errors. DeepSeek trains on a smaller volume of data (for example, 14.8 trillion tokens for V3), supplementing them with synthetic datasets and optimization for specific tasks. This approach makes DeepSeek faster, but sometimes less accurate when executing complex user requests.

Text Generation Quality

The quality of generated text is one of the most important criteria when evaluating language models. ChatGPT is traditionally considered the leader in creating natural, coherent, and stylistically rich texts. It can write essays in the style of literary classics, movie scripts, scientific articles, or even humorous dialogues.In 2025, new versions of the language model, such as GPT-4o and o1, significantly reduced the likelihood of producing erroneous statements, substantially improved the logical structure of texts, and increased accuracy in answering complex questions.

DeepSeek also demonstrates high-quality text creation. However, in complex creative tasks, DeepSeek falls short: its texts may be less elegant, and in long dialogues, it sometimes loses the thread of conversation or simplifies the style. Users note that DeepSeek handles short and medium requests better, while ChatGPT wins in multi-stage scenarios.

Generation speed is another important factor to consider. Thanks to MoE, DeepSeek processes requests faster, which is noticeable in mass text generation or under limited resource conditions. ChatGPT, on the other hand, requires more time for analysis and processing, but the result justifies expectations in tasks where depth and quality are important.

Coding and Programming

Programming and use in the IT industry is one of the most in-demand and popular functions of language models, but here DeepSeek and ChatGPT offer different approaches.

ChatGPT has established itself as a universal assistant for developers. It supports dozens of programming languages, can write code, explain algorithms, and find errors. In 2025, a deep reasoning mode was added, which allows the model to solve complex problems step by step. However, the free version of ChatGPT is limited in code volume and processing speed, forcing users to switch to paid plans.

Despite the fact that DeepSeek was originally designed with the needs of programmers and IT specialists in mind, it often exceeds expectations in this area. Its open-source code and free access have made it a hit among open-source communities. DeepSeek R1, for example, showed outstanding results in code writing: it generates working solutions faster than ChatGPT and often adds useful details, such as line comments, game score tracking, or performance optimization. Tests in SwiftUI, Go, and Python showed that DeepSeek sometimes surpasses ChatGPT in code readability and speed of executing simple tasks, although in complex implementations (such as multithreaded applications) it may fall short.

DeepSeek's special feature is DeepThink mode, which shows the step-by-step logic of solving a problem, which is ideal for learning and debugging. ChatGPT also offers similar functions, but only in paid versions, such as Advanced Reasoning. For simple tasks (writing a script or parsing data), DeepSeek wins thanks to speed and accessibility, but for large projects with long-term support, ChatGPT remains a more reliable choice.

Language Support

Multilingualism plays an important role for users around the world. ChatGPT supports over 50 languages, with a high level of accuracy and contextual understanding. It easily switches between languages within a single dialogue, maintaining natural communication. For example, a request in Spanish "Explain quantum entanglement in simple words" will be processed taking into account scientific terminology and adapted for a Spanish-speaking audience. ChatGPT also handles rare languages and dialects well, making it a universal tool for the global market.

DeepSeek is also multilingual and supports over 20 languages, including English, Chinese, Arabic, Spanish, Portuguese, and others. However, its performance in languages other than English and Chinese is sometimes lower due to a smaller volume of training data. For example, in long dialogues in Spanish, DeepSeek may accidentally switch to English or generate a less accurate translation of complex phrases. This is especially noticeable in technical or legal texts where high terminological accuracy is required. Nevertheless, for basic tasks such as translating instructions or writing simple texts, DeepSeek copes quite well.

Accessibility and Cost

Accessibility and cost are also key factors when choosing between DeepSeek and ChatGPT.

DeepSeek is distributed for free; however, API usage requires paid plans. The DeepSeek interface is accessible through a web browser on the official website and through a mobile application on iOS and Android. Access can also be obtained locally through the Ollama framework. Open-source code allows developers to customize the model to their needs, making it ideal for experiments, startups, and educational projects. By 2025, DeepSeek became a popular application in the App Store and Google Play, especially in Asian countries and Eastern Europe.

While ChatGPT is distributed under a Freemium model, it only offers a free basic version based on the GPT-4o mini model. This model has limitations on the number of requests sent and also imposes restrictions on text volume. Full access to models like GPT-4o or o1 requires a subscription, the cost of which ranges from $20 per month to hundreds of dollars for plans with API and increased limits.

DeepSeek wins in economy and ease of access, especially for users on a limited budget. ChatGPT offers more features for those willing to pay for premium functions, such as integration with external services, image generation, or working with large volumes of data.

Comparison Table

For clarity, we've compiled the main characteristics of the two AIs into a table for convenient comparison.

What to Choose: DeepSeek or ChatGPT?

The choice between the two chatbots DeepSeek and ChatGPT depends on user needs, budget, and, most importantly, the types of tasks that need to be solved.

DeepSeek is ideally suited for users who need a fast, free, and efficient tool for everyday tasks. Such tasks include writing source code for a small project, analyzing text documents, searching for information on the internet, or generating simple texts such as letters or notes. Its advantages are especially noticeable for students, beginning developers, small businesses, and enthusiasts, where resource conservation and the absence of entry barriers are important. Another advantage of DeepSeek is the lack of fees for using the chatbot itself. Payment is only required for users who plan to use the API.

ChatGPT, on the other hand, is better suited for complex tasks requiring high-quality text (including writing lengthy articles, scripts, business plans, etc.), deep analysis, or multi-stage reasoning. However, unlike DeepSeek, ChatGPT is distributed under a freemium model in which chatbot use is limited by the number of requests sent to the bot. The API is also paid and costs more than DeepSeek's API.

Examples of DeepSeek and ChatGPT Usage:

1. DeepSeek: Writing simple scripts for automating most types of tasks, searching for and generating technical material.
2. ChatGPT: Generating complex texts, for example, for creating stories with full plots, solving complex algebraic problems. Also suitable for processing large data and working with analytical material.

Conclusion

Both AI models have advantages and disadvantages.

Among DeepSeek's advantages are the lack of usage fees and speed of operation, making it a good solution for performing basic tasks. ChatGPT leads in text quality, versatility, and depth of analysis, which justifies its cost for professionals and complex projects.

Both models continue to evolve, and their competition contributes to progress in the field of AI. DeepSeek is suitable for those looking for an accessible, fast tool, while ChatGPT is for those ready to tackle large, universal tasks.