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 vs OpenAI: GPT-5.4 Nano
Inception: Mercury 2.5 and OpenAI: GPT-5.4 Nano are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
GPT-5.4 nano is the most lightweight and cost-efficient variant of the GPT-5.4 family, optimized for speed-critical and high-volume tasks. It supports text and image inputs and is designed for low-latency...
Model details →Side-by-side comparison
| Capability | Inception: Mercury 2.5 | OpenAI: GPT-5.4 Nano | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 260K | 400K | 🏆 OpenAI: GPT-5.4 Nano |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $0.04 | $0.20 | 🏆 Inception: Mercury 2.5 |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $0.15 | $1.25 | 🏆 Inception: Mercury 2.5 |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | Yes | Tie |
| Vision input Accepts image inputs alongside text. | — | Yes | 🏆 OpenAI: GPT-5.4 Nano |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is Inception: Mercury 2.5 better than OpenAI: GPT-5.4 Nano?
Inception: Mercury 2.5 and OpenAI: GPT-5.4 Nano are evenly matched on 6 axes — pick the one whose provider, latency, or licensing fits your stack.
What's the price difference between Inception: Mercury 2.5 and OpenAI: GPT-5.4 Nano?
Input: $0.04 vs $0.20 per 1M tokens. Output: $0.15 vs $1.25 per 1M tokens.
What context windows do Inception: Mercury 2.5 and OpenAI: GPT-5.4 Nano support?
Inception: Mercury 2.5 supports up to 260K tokens. OpenAI: GPT-5.4 Nano supports up to 400K tokens.
Do both Inception: Mercury 2.5 and OpenAI: GPT-5.4 Nano support tool calling?
Inception: Mercury 2.5: yes. OpenAI: GPT-5.4 Nano: yes.