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...
Model details →Inception: Mercury 2.5 Preview vs OpenAI: GPT-5 Nano (batch)
OpenAI: GPT-5 Nano (batch) wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
GPT-5-Nano is the smallest and fastest variant in the GPT-5 system, optimized for developer tools, rapid interactions, and ultra-low latency environments. While limited in reasoning depth compared to its larger...
Model details →Side-by-side comparison
| Capability | Inception: Mercury 2.5 Preview | OpenAI: GPT-5 Nano (batch) | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 260K | 400K | 🏆 OpenAI: GPT-5 Nano (batch) |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $0.04 | $0.03 | 🏆 OpenAI: GPT-5 Nano (batch) |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $0.15 | $0.20 | 🏆 Inception: Mercury 2.5 Preview |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | — | Yes | 🏆 OpenAI: GPT-5 Nano (batch) |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Inception: Mercury 2.5 Preview better than OpenAI: GPT-5 Nano (batch)?
OpenAI: GPT-5 Nano (batch) wins on 3 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between Inception: Mercury 2.5 Preview and OpenAI: GPT-5 Nano (batch)?
Input: $0.04 vs $0.03 per 1M tokens. Output: $0.15 vs $0.20 per 1M tokens.
What context windows do Inception: Mercury 2.5 Preview and OpenAI: GPT-5 Nano (batch) support?
Inception: Mercury 2.5 Preview supports up to 260K tokens. OpenAI: GPT-5 Nano (batch) supports up to 400K tokens.
Do both Inception: Mercury 2.5 Preview and OpenAI: GPT-5 Nano (batch) support tool calling?
Inception: Mercury 2.5 Preview: yes. OpenAI: GPT-5 Nano (batch): yes.