Mercury 3:
Speed vs Evidence
Inception's new diffusion language model promises unusually fast output at low launch pricing. Here's what is published, what is measured, and what remains uncertain.
01 / Generation speed
Inception-reported throughput on NVIDIA GPUs. This is not a head-to-head independent benchmark.
Mercury 3 · output tokens per second
02 / API pricing
USD per million tokens. Compare the same token category; lower is cheaper. Launch prices are temporary and have no published end date.
Input price · launch vs standard
Output price · launch vs standard
| Category | Launch | Standard |
|---|---|---|
| Input / 1M | $0.10 | $0.20 |
| Cached input / 1M | $0.01 | $0.02 |
| Output / 1M | $0.35 | $0.70 |
03 / Published quality results
Medium-reasoning scores attributed to Inception by BenchLM. Different benchmarks measure different abilities: do not treat the bar lengths as one unified ranking.
GPQA Diamond · knowledge/reasoning
IFBench · instruction following
DeepSWE v1 · software engineering
BrowseComp+ · web research
Additional reported results: MultiChallenge 60.35, MRCR v2 75.50, tau3-bench Banking 30.24, DeepSearchQA 71.33. Exact evaluation configurations and independent replication remain limited.
Why diffusion matters
Traditional autoregressive language models produce tokens sequentially. Diffusion language models iteratively refine multiple tokens in parallel. This can reduce generation latency, but speed alone does not guarantee correct code, robust tool use, or faster end-to-end agents.
What is actually available?
Mercury 3 is offered through Inception's API and announced via OpenRouter, Baseten and Vercel. The API is OpenAI-compatible. The model is proprietary: public weights are not available. The 100M-token offer applies to new accounts and is subject to provider terms.
What I'd test next
Run the same real coding-agent tasks through Mercury 3, DeepSeek V4.1 Flash and GLM-5.3 Flash. Record task success, first-token latency, end-to-end completion time, tool-call reliability and total billed tokens. Don't infer any of those results from vendor throughput alone.
Sources
- Inception — Mercury 3 launch, Oct 19, 2026
- Inception — official pricing
- Vercel AI Gateway — API specifications and pricing
- BenchLM — provider-reported benchmark evidence and caveats