--- title: "Mercury 2.5 Preview AI model: facts and benchmarks | Kendr" canonical: "https://kendr.org/models/inception-mercury-2-5-preview" date_modified: "2026-09-06" profile_kind: "reference" --- # Mercury 2.5 Preview model profile Mercury 2.5 Preview is a Inception Labs model profile with a 260,000-token context window. The dated catalog snapshot records text modalities and interfaces for prompt caching, reasoning controls, structured output, text generation, tool calling. Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception. Instead of generating tokens sequentially, Mercury 2.5 produces and refines multiple tokens in parallel, achieving... Mercury 2.5 Preview is a reference profile: Inception Labs publishes it, Kendr documents it for comparison, and it carries no Kendr alias to call. Mercury 2.5 Preview is an independent knowledge profile. It does not claim that Kendr hosts the model, quote a Kendr customer price, promise API availability, or advertise a Kendr routing receipt. Mercury 2.5 Preview accepts text and returns text. The snapshot records prompt caching, reasoning controls, structured output, text generation, and tool calling as capabilities or interfaces. The dated reference snapshot lists $0.04 input and $0.15 output per million tokens. Cached input is $0.004 per million tokens. No comparable third-party benchmark value is present in the 2026-09-06 snapshot. Missing values are not estimated. No comparable popularity rank or traffic share is present in the 2026-09-06 snapshot. No comparable routing rank or traffic-share observation is attached to this dated profile; missing adoption evidence is not estimated. Profile data was reviewed for the 2026-09-06 snapshot. Claims retain their source dates, and unavailable fields are shown as unavailable instead of estimated. ## Profile facts - **Profile type:** Model research profile - **Provider or publisher:** Inception Labs - **Context window:** 260,000 tokens - **Snapshot date:** 2026-09-06 - **Knowledge cutoff:** Not disclosed - **Reference catalog ID:** inception/mercury-2.5-preview ## When to pick Mercury 2.5 Preview Mercury 2.5 Preview is a reference profile: Inception Labs publishes it, Kendr documents it for comparison, and it carries no Kendr alias to call. Each condition below is derived from this model's own values in the 2026-09-06 snapshot, compared only against models publishing the same field. - Reach for it when cost is the binding constraint. At $0.04 in and $0.15 out per 1M tokens, combined token price sits in the cheapest quarter of the 146 models publishing both rates in this snapshot. - Reach for it when the model has to call tools. Tool calling is recorded in the snapshot, so this route can drive an agent loop rather than only answer in prose. - Reach for it when you want to trade depth against cost per call. Reasoning effort is selectable across high, medium, low, none, so one route can serve both cheap and deep work. - Look elsewhere when you need to call it through Kendr today. This is a research reference profile with no Kendr alias. The facts and evidence here are published for comparison; the model is not routable on Kendr. - Look elsewhere when the workload is production traffic. The catalog marks this model preview. Preview routes can change behaviour or availability without the notice a stable route carries. ## Context, modalities, and identity Mercury 2.5 Preview accepts text and returns text. The snapshot records prompt caching, reasoning controls, structured output, text generation, and tool calling as capabilities or interfaces. - **Provider or publisher:** Inception Labs - **Context window:** 260,000 tokens - **Maximum output:** 65,536 tokens - **Input modalities:** text - **Output modalities:** text - **Knowledge cutoff:** Not disclosed ## Model overview Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception. Instead of generating tokens sequentially, Mercury 2.5 produces and refines multiple tokens in parallel, achieving... - **Reference model ID:** inception/mercury-2.5-preview - **Canonical version:** inception/mercury-2.5-preview-20260831 - **Hugging Face ID:** Not separately documented ## Capabilities and supported controls Capabilities and parameters are reported from the dated catalog and source records; their presence does not guarantee identical behavior across every provider route. - **Supported parameters:** include_reasoning, max_tokens, reasoning, reasoning_effort, response_format, stop, structured_outputs, temperature, tool_choice, tools - prompt caching - reasoning controls - structured output - text generation - tool calling ## Dated pricing snapshot The dated reference snapshot lists $0.04 input and $0.15 output per million tokens. Cached input is $0.004 per million tokens. These are dated third-party reference prices, not Kendr prices or an availability offer. Routes, tiers, caching, region, and provider policy can change the landed price. - **Price date:** 2026-09-06 - **Input:** $0.04 per 1M tokens - **Cached input:** $0.004 per 1M tokens - **Output:** $0.15 per 1M tokens ## Provider routes, performance, and uptime The snapshot retains 1 provider endpoint. Provider prices, context limits, p50 performance, and uptime can differ by route and are not Kendr guarantees. - **Active provider endpoints:** 1 - **Best p50 latency:** No recent metric - **Best p50 throughput:** No recent metric - **Availability with routing:** No recent metric - **Availability without routing:** No recent metric - **Performance date:** 2026-09-06 | Provider | Quantization | Input / 1M | Output / 1M | Cache read / 1M | Context | p50 latency | p50 throughput | Uptime (1d) | | --- | --- | --- | --- | --- | --- | --- | --- | --- | | Inception | unknown | $0.04 / 1M | $0.15 / 1M | $0.004 / 1M | 260,000 tokens | No recent p50 | No recent p50 | 100.00% | ## Benchmark evidence and limitations No comparable third-party benchmark value is present in the 2026-09-06 snapshot. Missing values are not estimated. Third-party catalog fields normalized from the cited model dataset; benchmark methodology and coverage differ by source. ## Popularity and market context No comparable popularity rank or traffic share is present in the 2026-09-06 snapshot. No comparable routing rank or traffic-share observation is attached to this dated profile; missing adoption evidence is not estimated. - **Third-party catalog rank:** No verified rank - **Global market share:** Not inferred - **Observation date:** 2026-09-06 ## Frequently asked questions ### When should I use Mercury 2.5 Preview? Mercury 2.5 Preview is a reference profile: Inception Labs publishes it, Kendr documents it for comparison, and it carries no Kendr alias to call. Reach for it when cost is the binding constraint: At $0.04 in and $0.15 out per 1M tokens, combined token price sits in the cheapest quarter of the 146 models publishing both rates in this snapshot. Reach for it when the model has to call tools: Tool calling is recorded in the snapshot, so this route can drive an agent loop rather than only answer in prose. Reach for it when you want to trade depth against cost per call: Reasoning effort is selectable across high, medium, low, none, so one route can serve both cheap and deep work. Look elsewhere when you need to call it through Kendr today: This is a research reference profile with no Kendr alias. The facts and evidence here are published for comparison; the model is not routable on Kendr. Look elsewhere when the workload is production traffic: The catalog marks this model preview. Preview routes can change behaviour or availability without the notice a stable route carries. ### What is Mercury 2.5 Preview? Mercury 2.5 Preview is a Inception Labs model profile with a 260,000-token context window. The dated catalog snapshot records text modalities and interfaces for prompt caching, reasoning controls, structured output, text generation, tool calling. ### What context window does Mercury 2.5 Preview have? The dated profile lists 260,000 tokens of context and up to 65,536 output tokens. Provider routes, variants, and runtime configuration can impose lower effective limits. ### What benchmark evidence is available for Mercury 2.5 Preview? No comparable third-party benchmark value is present in the 2026-09-06 snapshot. Missing values are not estimated. Third-party catalog fields normalized from the cited model dataset; benchmark methodology and coverage differ by source. ### Is Mercury 2.5 Preview available through Kendr? This is an independent knowledge profile, not a Kendr-hosted availability claim. Check Kendr's live public model API for currently enabled Kendr aliases. ### Does the popularity rank represent Mercury 2.5 Preview's global market share? No comparable popularity rank or traffic share is present in the 2026-09-06 snapshot. No comparable routing rank or traffic-share observation is attached to this dated profile; missing adoption evidence is not estimated. No global market-share percentage is inferred when the source does not publish one. ## Sources and evidence dates - [Mercury 2.5 Preview third-party catalog record](https://openrouter.ai/inception/mercury-2.5-preview) — catalog, checked 2026-09-06 - [Third-party model catalog methodology](https://openrouter.ai/docs/guides/overview/models) — methodology, checked 2026-09-06 - [Inception Labs official model documentation](https://docs.inceptionlabs.ai/) — primary, checked 2026-09-06 Live Kendr operational availability is published separately at https://api.kendr.org/api/public/models.