Inception · Released Sep 8, 2026Mercury 2.5
Mercury 2.5 is the fastest reasoning LLM, and the latest diffusion LLM (dLLM) from Inception.
- Capability
- —No ECI score yet
- Input
- $0.04per 1M tokens
- Output
- $0.15per 1M tokens
- Context
- 260K66K max output
What it costs
- Input
- $0.04per million tokens
- Output
- $0.15per million tokens
- Cached input
- $0.004per million tokens
- Blended (3:1)
- $0.068cheaper than 95% of priced models
Typical monthly bills
| Monthly usage | Estimated cost |
|---|---|
| Side project2M input + 0.5M output tokens | $0.155 |
| Team assistant25M input + 5M output tokens | $1.75 |
| Production app250M input + 50M output tokens | $17.50 |
Official Inception API price, as listed on models.dev.
Independent benchmarks
Epoch AI has not published a Capabilities Index score for Mercury 2.5 yet.
The details
- Lab
- Inception
- Released
- Sep 8, 2026
- Knowledge cutoff
- Nov 1, 2025
- Context window
- 260,000 tokens
- Max output
- 65,536 tokens
- Inputs
- Text
- Output
- Text
- Reasoning
- Adjustable effort low · medium · high
- Tool calling
- Yes
- Structured output
- Yes
- Weights
- Proprietary
- API model ID
mercury-2.5on Inception- Availability
- 1 API providerlisted on models.dev
More from Inception
About Mercury 2.5
How much does Mercury 2.5 cost?
Mercury 2.5 costs $0.04 input / $0.15 output per million tokens (official Inception API price). Cached input is $0.004 per million tokens. At a 3:1 input-to-output mix that is $0.068 per million tokens, cheaper than 95% of the 360 priced models we track.
What is the context window of Mercury 2.5?
Mercury 2.5 accepts up to 260,000 tokens per request and can write up to 65,536 tokens in one response.
How good is Mercury 2.5?
Epoch AI has not published a Capabilities Index score for Mercury 2.5 yet.
Is Mercury 2.5 open source?
No. Mercury 2.5 is proprietary; you use it through Inception’s API or partner platforms.
What inputs does Mercury 2.5 support?
Mercury 2.5 accepts text and replies in text. It is a reasoning model with low, medium and high effort settings, supports tool calling and can return structured JSON output.
When was Mercury 2.5 released?
Inception released Mercury 2.5 on Sep 8, 2026. Its training data runs to Nov 1, 2025.
What are the best alternatives to Mercury 2.5?
The closest current models from other labs on capability, price and release date are Laguna XS 2.1 (Poolside, $0.06 / $0.12), Nemotron 3.5 Lightning 30B A3B (NVIDIA, $0.05 / $0.20), Ling 3.0 Flash Fin (inclusionAI, $0.075 / $0.22) and Gemma 4 E2B IT (Google, $0.07 / $0.09).