Mercury 3: a diffusion language model that writes over 1,000 tokens a second

Inception released Mercury 3 on Monday. Most chatbots write one word piece at a time. Mercury 3 is a diffusion model: it drafts the whole answer at once and refines it in a few passes. Inception says it matches or beats OpenAI's GPT-6 Luna and Anthropic's Claude Haiku 5.5 on its benchmarks while generating 1,068 tokens per second on Nvidia GPUs. It has a one-million-token context window, up from 260,000 for Mercury 2.5. List price is $0.20 per million input tokens and $0.70 per million output tokens, and it's half price at launch ($0.10 and $0.35). Cached input is 90% off. You can use it through Inception's own API, where new keys get 100 million free tokens, and through OpenRouter, Baseten and Vercel's AI Gateway. It works as a drop-in for code written for OpenAI's API.

What this means for you: speed is the selling point. It suits voice assistants, live chat, real-time search and browser agents, where waiting for a reply hurts the experience. All of the quality claims come from Inception itself, and nobody has independently checked them yet, so test it on your own prompts. If you use Mercury 2 or 2.5, take note: both are closed to new users, and existing customers with usage before Oct 19 keep access only until Nov 15, 2026, so plan your move.