DeepSeek

DeepSeek is an AI assistant and model platform built around the company's open-source large language models, offering conversational chat, deep reasoning ('deep thinking'), and intelligent search through a free web app, mobile apps, and a paid developer API. It serves both everyday users who want a free ChatGPT-style assistant and developers who want to build on capable models via API. Its main differentiator is delivering strong reasoning, coding, and now native multimodal vision (in DeepSeek-V4.1-Flash) at notably lower cost than comparable proprietary models, with open weights.