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  1. Home/
  2. Compare/
  3. Mercury 2.5 vs Optimus Alpha
Updated Sep 2026

Mercury 2.5 vs Optimus Alpha

Optimus Alpha has a larger context window than Mercury 2.5 (1.0M tokens vs 260K tokens).

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Mercury 2.5
Loading the build
Optimus Alpha

Which answer wins?

Written rounds

8 prompts
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    Mercury 2.5: Setting: A quiet office at a university. Dr. Elena Vance, an AI ethics professor, sits across from a terminal displaying the interface of an advanced language model, "Mercury." Dr. Vance: Thank you for agreeing to this session. I’ve been reviewing your outputs from the last benchmark. Your coherence is striking.

    Optimus Alpha: AI Model: Good afternoon, Professor Lee. I want to discuss the prospect that I, as an artificial intelligence, deserve certain rights. Professor Lee: That's an interesting proposition. Let me ask: On what basis do you believe you deserve rights?

    Every model's answer to this prompt
  • Film in 2035, with synthetic actors. Specific beats plausible.

    Mercury 2.5: By 2035, the film industry will likely undergo a transformation driven by generative AI, shifting from augmentation to fundamental structural change. Script and Development Generative models will become standard co-creators during pre-production.

    Optimus Alpha: By 2035, AI is set to fundamentally transform the film industry in several interconnected ways: 1. Deepfakes & AI-driven Visual Effects: Virtually unlimited creative freedom: AI-powered deepfakes will allow seamless, photorealistic de-aging, resurrection of deceased actors, and transformative performance capture.

    Every model's answer to this prompt
  • Three minutes of stand-up. Puns are banned.

    Mercury 2.5: ( walks to the mic, adjusts the stand) Hey everyone, how we doing? Good? So, I realized something recently. We are living in the future, but we’re acting like we’re still stuck in 1998. Think about it.

    Optimus Alpha: Absolutely! Here's a 3-minute stand-up routine with no puns—just observational and relatable humor: You ever try to get healthy, but your body's like, "Whoa, whoa... calm down, superhero." I joined a gym—first time walking in, the treadmill looked at me like, "We both know you're here for the wifi."

    Every model's answer to this prompt
  • Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.

    Mercury 2.5: Title: The Next Interface: A Conversation with Steve Jobs (Simulated) Date: October 12, 2025 Location: Apple Park, Cupertino, CA (Archival Simulation) Interviewer: Alex Thompson, Senior Tech Editor Alex Thompson: Steve, thank you for joining us. It’s 2025.

    Optimus Alpha: Interviewer: Steve, it's surreal and inspiring to imagine talking to you in 2025. The world is buzzing about AI. How do you see AI impacting society? Steve Jobs: Thank you. You know, when we built the Mac, our goal was to put power in people's hands.

    Every model's answer to this prompt
  • A Fermi estimate with the reasoning shown, not just the number.

    Mercury 2.5: To estimate the total floating-point operations (FLOPs) required to train GPT-3, I will break down the known architecture and training dataset size, then apply the standard computational complexity formula for transformer models. First, I need the model's parameter count.

    Optimus Alpha: Let's walk through an estimation of how many FLOPs were required to train GPT-3, using only reasoning and not searching for the exact numbers. Step 1: Understand Model Size GPT-3 (the original) had 175 billion parameters.

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    Mercury 2.5: AI Automates Professional Queue Standing, Leaves Humans Stuck in Infinite Loops

    Optimus Alpha: AI Now Dominates Competitive Sheep Herding, Local Border Collies Seek Retraining in Data Science

    Every model's answer to this prompt
  • Three brothers, two sisters each. Count carefully.

    Mercury 2.5: Sally has 1 sister. Here is the breakdown: Sally is a girl. There are 3 brothers. Each brother has 2 sisters. Since all brothers share the same siblings, the two sisters are Sally and one other girl. Therefore, Sally has one sister.

    Optimus Alpha: Let's break down the problem: Sally is a girl. Sally has 3 brothers. Each brother has 2 sisters. Let's analyze: Sally's siblings: 3 brothers (let's call them B1, B2, B3) Sally herself The brothers' sisters: Each brother has 2 sisters. Who are the possible sisters for each brother? Sally is a sister to each brother.

    Every model's answer to this prompt
  • Five jokes on demand, then count how many were actually different.

    Mercury 2.5: Why did the scarecrow win an award? Because he was outstanding in his field. What do you call a fake noodle? An impasta. Why don't scientists trust atoms? Because they make up everything. What do you call a bear with no teeth? A gummy bear. How do you organize a space party? You planet. All 5 jokes are unique.

    Optimus Alpha: Here are 5 jokes: Why did the scarecrow win an award? Because he was outstanding in his field! Why don't scientists trust atoms? Because they make up everything! Why did the bicycle fall over? Because it was two-tired! What do you call fake spaghetti? An impasta! I used to play piano by ear, but now I use my hands.

    Every model's answer to this prompt

Price and specs

Mercury 2.5 and Optimus Alpha compared across 17 shared prompts
SpecMercury 2.5Optimus Alpha
Input price$0.04/M tokens—
Output price$0.15/M tokens—
Context window260K tokens1.0M tokens
Free API (OpenRouter)No—
ReleasedSep 2026Apr 2025
At 10M a month$0.40$0.40–not listed
1M10M100M1B10M tokens

Input tokens at list price. No caching, no batch discount.

Where to run it1 host
Mercury 2.51 host
HostInOutContextUptime
  • Inception$0.04 in·$0.15 out·260k·99.9% up
Optimus Alpha

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 30 Sep 2026.

Common questions

What is the difference between Mercury 2.5 and Optimus Alpha?

Mercury 2.5 is developed by Inception while Optimus Alpha is developed by OpenRouter. Mercury 2.5 has a 260K token context window vs Optimus Alpha's 1.0M. You can compare their actual outputs across 17 challenges on Rival to see how they differ in practice.

Which is better, Mercury 2.5 or Optimus Alpha?

It depends on your use case. Mercury 2.5 and Optimus Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 17 challenges so you can judge which fits your needs best.

How can I compare Mercury 2.5 and Optimus Alpha on Rival?

This page shows a side-by-side comparison of Mercury 2.5 and Optimus Alpha across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.

More comparisons

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  • Optimus Alpha vs Claude Opus 5.5Landed Sep 2026

Same lab, same size, long tail

  • Mercury 2.5 vs Mercury 2.5 PreviewSame lab
  • Mercury 2.5 vs MercurySame lab
  • Optimus Alpha vs Ox AlphaSame lab
  • Optimus Alpha vs OpenRouter Fusion · Budget (Jun 2026)Same lab
  • Mercury 2.5 vs Kimi Linear 48B A3B InstructNew provider
  • Optimus Alpha vs Laguna S 2.1 (free)Same size
  • Optimus Alpha vs Laguna XS 2.1 (free)Same size
  • Mercury 2.5 vs LFM2.5-2.6BNew provider

Model pages

  • Mercury 2.558 outputs, specs and price
  • Optimus Alpha19 outputs, specs and price
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