Mercury 2.5
Summary
Mercury 2.5 is a proprietary language model from Inception Labs, released on 8 Sept 2026. It accepts text and generates text, with a 260K-token context window and up to 66K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $0.04 per million input tokens and $0.15 per million output tokens (Inception API), across 2 providers we track.
Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | Inception Labs |
|---|---|
| Release date | 8 Sept 2026 [models.dev] |
| Status | Generally available [models.dev] |
| Weights | Proprietary (API only) [models.dev] |
| Context window | 260K (260,000 tokens) [models.dev] |
| Max output | 66K tokens [models.dev] |
| Knowledge cutoff | 1 Nov 2025 [models.dev] |
| Input | Text [models.dev] |
| Output | Text [models.dev] |
| Reasoning mode | Yes [models.dev] |
| Tool calling | Yes [models.dev] |
| Structured output | Yes [models.dev] |
Mercury 2.5 API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| Inception API mercury-2.5 | $0.04 | $0.15 | $0.004 | 260K | models.dev, 4 Oct 2026 |
| OpenRouter inception/mercury-2.5 | $0.04 | $0.15 | $0.004 | 260K | OpenRouter, 4 Oct 2026 |
Frequently asked questions
What is the context window of Mercury 2.5?
Mercury 2.5 has a context window of 260,000 tokens (260K) and can generate up to 65,536 tokens in a single response, according to models.dev.
How much does the Mercury 2.5 API cost?
Through Inception API, Mercury 2.5 costs $0.04 per million input tokens and $0.15 per million output tokens. Prices last verified 4 Oct 2026.
Is Mercury 2.5 open source?
No. Mercury 2.5 is a proprietary model; Inception Labs has not released its weights. It is available through APIs including Inception API, OpenRouter.
When was Mercury 2.5 released?
Inception Labs released Mercury 2.5 on 8 Sept 2026, according to models.dev.
Which providers offer Mercury 2.5?
We track Mercury 2.5 on 2 providers: Inception API, OpenRouter.
Change history
No changes detected since we started tracking this model. We re-check every source daily.