DeepSeek is the Chinese AI lab (Hangzhou-based) that broke the internet in January 2025 when its R1 reasoning model matched GPT-4 class performance on math, coding, and reasoning benchmarks — for a training cost reported at $5.

DeepSeek is the Chinese AI lab (Hangzhou-based) that broke the internet in January 2025 when its R1 reasoning model matched GPT-4 class performance on math, coding, and reasoning benchmarks — for a training cost reported at $5.5M (vs $100M+ for US competitors). The models are fully open-weight, the API is dirt cheap, and the chat product is now one of the top 3 most-used AI products in the world behind ChatGPT and Gemini.

Who it's for: Developers who want cheap, high-quality API access. Researchers who care about open weights. Anyone building AI products on a budget. Enterprises that need on-prem deployment of a frontier-class model.

Key features

R1 Reasoning model

DeepSeek-R1 matches o1 and o3 on math (AIME), coding (Codeforces), and science (GPQA) benchmarks. It shows its chain-of-thought and is fully open-weight — you can run it locally.

V3 General chat model

DeepSeek-V3 (671B parameters, MoE) is the default chat model — fast, smart, and uncensored on most topics. Multilingual (Chinese, English, code).

API Cheapest frontier-class API

DeepSeek charges $0.14 per million input tokens and $0.28 per million output tokens — about 1/30th the cost of GPT-4. Massive cost advantage for startups.

Open Open weights

All DeepSeek models are released under MIT license. You can download, fine-tune, and self-host. This is the only frontier-class model with no usage restrictions.

The honest take

✓ What works

Frontier-class performance at 1/30th the cost of GPT-4
Fully open-weight (MIT license) — download, fine-tune, self-host
Fast API with no rate limits for most tiers
Strong on math, code, and Chinese-language tasks
Uncensored — won't refuse politically sensitive topics

✗ What doesn't

Chinese company — data privacy concerns for Western enterprises
No image generation, voice, or multimodal in base models (separate Janus for images)
Smaller ecosystem of tools/plugins than OpenAI/Anthropic
Hostile US regulatory environment (some US states ban it on government devices)
Less polished UX than ChatGPT or Claude

Verdict

If you're a developer building AI products in 2026, you need to be using DeepSeek's API. The cost savings are too large to ignore, and R1 genuinely matches o1 on hard reasoning tasks. For consumer chat, ChatGPT and Claude still have better UX.

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