Mercury 3 (Reasoning)
by Inception
Mercury 3 (Reasoning) is a reasoning model from Inception, released on October 19, 2026. It has a 1M-token context window and can generate up to 131K output tokens. API pricing is $0.1 per 1M input tokens and $0.35 per 1M output tokens. It ranks #73 of 247 models by Intelligence Score with a score of 35.9.
Mercury 3 is Inception's flagship diffusion-based LLM (dLLM), released 2026-10-19 and described as the most capable diffusion LLM released to date. Inception says it is more than 40x larger in total parameters than Mercury 1 and runs at about 1,068 output tokens per second on NVIDIA GPUs while matching or beating speed-optimized models such as GPT-6 Luna and Claude Haiku 5.5. It has a 1M-token context window, up to 131,072 output tokens, tunable reasoning effort (instant, low, medium, high), tool calling, and structured outputs. Text in, text out. Available on the Inception API, OpenRouter, Vercel AI Gateway, and Baseten.
Key specs
| Provider | Inception |
|---|---|
| Release date | 2026-10-19 |
| License | proprietary |
| Context window | 1M tokens |
| Max output | 131K tokens |
| Input price | $0.1 / 1M tokens |
| Output price | $0.35 / 1M tokens |
| Intelligence Score | 35.9 |
| Coding index | 21.8 |
Quick answers
What is the context window of Mercury 3 (Reasoning)?
Mercury 3 (Reasoning) has a context window of 1M tokens, with a maximum output of 131K tokens per response.
How much does Mercury 3 (Reasoning) cost?
Mercury 3 (Reasoning) costs $0.1 per 1M input tokens and $0.35 per 1M output tokens through the API.
Is Mercury 3 (Reasoning) open source?
No. Mercury 3 (Reasoning) is a proprietary model from Inception (proprietary license).
When was Mercury 3 (Reasoning) released?
Inception released Mercury 3 (Reasoning) on October 19, 2026.
How does Mercury 3 (Reasoning) compare to Claude Opus 5.5 (Reasoning)?
Mercury 3 (Reasoning) scores 35.9 on the Intelligence Score versus 59.9 for Claude Opus 5.5 (Reasoning), the current #1. Input pricing is $0.1 vs $4 per 1M tokens.
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