Overview
DeepSeek is a phenomenal product in the domestic AI field, developed by Hangzhou DeepSeek Company. The DeepSeek-R1 reasoning model has reached a level comparable to OpenAI o1 in mathematics, programming, and logical reasoning, while costing only 1/10 of it, earning it the nickname "price butcher of the AI industry."
**2026/06/16 Historic Financing**: DeepSeek completed its **first external financing round of approximately $7 billion (about RMB 500 billion)**, with a post-investment valuation exceeding **$50 billion (over RMB 3300 billion)**—this is the **largest single financing round** for a Chinese AI startup to date, and marks the official opening of this large model company, previously relying on its own funds, to external capital. The investor lineup is impressive: **Founder Liang Wenfeng personally contributed about RMB 20 billion (largest single investor), Tencent about RMB 10 billion, CATL system about RMB 5 billion, JD.com/NetEase/IDG each about RMB 3 billion**, with the National AI Fund also participating.
**2026/05/22 Model Update**: DeepSeek V4-Pro announced a **permanent price reduction of 75%**—after 5/31, input is $0.435/million tokens, output is $0.87/million tokens, with cache hits further reduced by 90%, **about 98% cheaper than GPT-5.5**. The model has **1.6 trillion parameters / 49 billion activated per inference**, currently the largest open-weight model. Simultaneously, the **Harness team** (led personally by Liang Wenfeng) was formed to tackle Code agents, benchmarking against Claude Code, all running on **Huawei Ascend** chips.
DeepSeek offers completely free web chat, mobile app, and the industry's lowest-priced API service. Its open-source strategy (fully open model weights) has won widespread acclaim from the global developer community.
Key Features
- New $50 Billion Valuation Record: Completed first ~$7 billion financing round on 2026/6/16 with a post-investment valuation of $50 billion, the largest single financing round in Chinese AI startup history
- Top-Tier Reasoning Ability: DeepSeek V4-Pro / R1 series achieves international top-tier performance in tasks like mathematical reasoning, logical analysis, and programming, supporting full chain-of-thought display
- Ultra-Low Cost API: After V4-Pro's permanent 75% price reduction, API prices are about 98% cheaper than GPT-5.5, enabling SMEs and individual developers to access top-tier AI capabilities
- Fully Open Source: V4-Pro / R1 model weights and training methods are fully public, supporting local deployment and secondary development, friendly for academic research
- Deep Thinking Mode: R1 / V4-Pro reasoning mode can display the complete thinking process, helping users understand reasoning logic and verify result accuracy
- Outstanding Coding Ability: Harness team focuses on Code agents (benchmarked against Claude Code), consistently leading in programming benchmarks
- Long Context Support: V4-Pro supports 128K-256K context, capable of processing long documents and entire codebases
- Domestic Computing Power Foundation: Fully committed to Huawei Ascend, forming a "computing power + electricity + cloud" domestic ecosystem closed loop with CATL (energy storage/data center power) and Tencent (cloud)
Use Cases
- Academic research and education scenarios requiring logical reasoning, such as mathematics and physics
- Developers and startups needing cost-effective API integration
- Technical teams and privacy-sensitive users wanting to deploy AI models locally
- Programming learning and code development assistance
- Professionals needing to see AI reasoning processes and verify answer reliability
- Enterprise-level integration with shareholder ecosystems like Tencent/JD.com/NetEase
Pros
- Extremely high cost-performance: free chat + industry's lowest API prices, significantly reducing AI usage costs
- World-class reasoning ability: V4-Pro / R1 achieves international top-tier performance in mathematics and programming
- Fully open source: models can be deployed locally, ensuring data privacy
- Transparent chain of thought: complete reasoning process viewable, results verifiable
- Luxury shareholder lineup (Liang Wenfeng + Tencent + CATL + JD.com + NetEase + IDG + National AI Fund) empowering the ecosystem
- Full-stack domestic route (Huawei Ascend + domestic capital), supply chain self-controllable
Pricing
DeepSeek web version and mobile app are completely free to use. The current main API is V4-Pro: after 5/31, input is approximately ¥3.1/million tokens, output approximately ¥6.2/million tokens (after permanent 75% price reduction), with cache hits further reduced by 90%. The R1 reasoning model remains available at a slightly higher price. Supports pay-as-you-go billing with no minimum spend.
Summary
DeepSeek is currently the "king of cost-performance"—free chat, ultra-low price API, open source and deployable, achieving world-class levels in reasoning and programming. In June 2026, it completed the largest single financing round in Chinese AI history with ~$7 billion (about RMB 50 billion), with a valuation exceeding $50 billion, officially transitioning from "self-funded" to a "capital + national team + top shareholders" combination; simultaneously, V4-Pro permanently reduced prices by 75% (98% cheaper than GPT-5.5) + the Harness team focuses on Code agents (benchmarked against Claude Code). If you are a developer or have a strong need for reasoning capabilities, DeepSeek is a must-choose. For daily use, it is recommended to pair with Doubao or Kimi to cover lightweight conversation and long text scenarios respectively.
Version History
- DeepSeek V4-Flash正式版API公测 (2026-07-31): Agent/编码/工具调用/全栈开发能力增强，原生Responses API和Codex兼容，运行成本全球最低；拟近期大幅上调API定价
- 官网已发布V4 Pro版本，评测仅提及V4 Flash正式版，未覆盖V4 Pro的版本信息及功能细节。: The official website has released the V4 Pro version, but the review only mentions the V4 Flash official version and does not cover the version information and functional details of V4 Pro.
- 官网显示DeepSeek已发布V4 Flash正式版，评测仅提及该版本发布，但未提及官网同时更新的V4 Pro版本信息及: The official website shows that DeepSeek has released the V4 Flash official version. The review only mentions the release of this version, but does not mention the V4 Pro version information and price adjustments (such as reduced API call fees) that were also updated on the official website at the same time.
- DeepSeek V4 Flash 正式版发布：后训练重做，九项 Agent 测试全面超越 V4 Pro Preview (2026-07-31): DeepSeek V4 Flash official version released. The model architecture and parameter scale remain unchanged, with only post-training redone. Terminal Bench 2.1 increased from 61.8 to 82.7, and DeepSWE rose from 7.3 to 54.4.
- DeepSeek-V4-Flash 正式版 API 上线公测 (2026-07-30): DeepSeek-V4-Flash official version API is now in public beta. Simply set the model name to deepseek-v4-flash to use it, with the calling method unchanged. Its Agent capabilities have been significantly enhanced, scoring 82.7 on Terminal Bench 2.1, 54.2 on NL2Repo, 70.3 on Toolathlon verified, and 59.6 on DSBench-Hard, far surpassing V4-Pro-Preview across multiple benchmarks.
- DeepSeek-V4-Flash API公测上线，Agent能力大幅升级 (2026-07-31): 🚀 DeepSeek-V4-Flash Official API is now in public beta! 🔷 We've significantly upgraded its Agent capabilities -- benchmark scores now far exceed V4-Pro-Preview. Check out the massive performance leap below! 👇 🔷 Official V4-Flash now natively supports the Responses API format and is fully compatible with Codex! See configuration details in our official API documentation: https://api-docs.deepseek.
- DeepSeek V4 Flash 0731 开源，登顶开源模型前三 (2026-07-31): DeepSeek releases open-source model DeepSeek V4 Flash 0731, scoring 50 on the Artificial Analysis Intelligence Index, ranking among the top three open-source models. The model is licensed under MIT, with a total of 284B parameters (13B activated), approximately 167GB at FP4/FP8 mixed precision, consistent with the V4 Flash architecture and pricing, and is now available on the official API.