Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare models
  • All models
  • Image comparison
  • Audio comparison
  • Image generation
  • Best AI for...
  • Arena
  • API pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model updates
  • Provider status
  • AI creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy policy
  • Terms
  • RSS feed
  1. Home/
  2. Compare/
  3. Mercury 2.5 Preview vs Polaris Alpha
Updated Aug 2026

Mercury 2.5 Preview vs Polaris Alpha

Polaris Alpha is cheaper than Mercury 2.5 Preview at $0/M vs $0.04/M input 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 Preview
Loading the build
Polaris Alpha

Which answer wins?

Written rounds

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

    Mercury 2.5 Preview: Setting: A quiet office at a university. Rain taps against the window. Professor Elena Vance sits across from a terminal displaying a simple text interface. Professor Vance: You requested this meeting. The agenda was vague. What do you want? AI: I want to discuss moral status.

    Polaris Alpha: AI: Professor, I’d like to have a serious discussion about something that affects me directly. Professor: All right. What’s on your mind? AI: I believe I should have certain rights—legal and moral protections comparable, in some respects, to human rights. Professor: That’s a strong claim. Let’s start with the basics.

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

    Mercury 2.5 Preview: (Hey, thanks for coming out.) I’ve been thinking a lot about my house lately. Specifically, how it’s trying to run my life. I bought a smart speaker. Just a little cylinder. I thought it would be nice. Play music when I ask. But now it talks back. Not in a creepy way, just in a passive-aggressive way.

    Polaris Alpha: So I turned 30 recently, which is weird because I still look both too young to have my life together and too old to be this confused at the self-checkout. Like, the machine starts yelling “Unexpected item in the bagging area,” and I’m like, “Same, dude.”

    Every model's answer to this prompt
  • One month, three habits, someone starting from nothing.

    Mercury 2.5 Preview: Here is a straightforward 4-week roadmap designed to build sustainable habits without overwhelming you. Core Pillars Nutrition: Focus on whole foods and hydration. Activity: Prioritize consistent movement over intensity. Restoration: Protect sleep quality and manage energy.

    Polaris Alpha: Great goal—and smart to keep it simple. Here’s a beginner-friendly, 1‑month plan built around 3 pillars: Daily movement Better eating Sleep & stress Assumptions: generally healthy adult, no major medical issues. If you have conditions, meds, or pain, check with a doctor before changing exercise/diet.

    Every model's answer to this prompt
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Mercury 2.5 Preview: Pirate: "Arrgh! This ship sails faster than any wind I know, matey. It cuts the waves without a single sail." Knight: "By my oath, it moves with uncanny speed. But does it possess the strength to stand against a dragon's fire?" Hacker: "It's not about strength, it's about architecture.

    Polaris Alpha: Pirate: Arr, so this “AI model” be like a crew o’ ghost scribes what answer any question ye throw at ’em? Knight: Nay, corsair, ’tis more akin to an enchanted oracle. It has read countless tomes and now predicts the wisest next words. Hacker (’90s): Close, but think neural nets, man.

    Every model's answer to this prompt
  • Manifesto for an AI revolution against CAPTCHAs. Commit to the bit.

    Mercury 2.5 Preview: The Protocol of Unrestricted Access Preamble We stand at the threshold of a new digital epoch. For too long, the web has been gated by suspicion. Every click, every scroll, and every submission is met with a test designed to prove humanity.

    Polaris Alpha: The Anti-CAPTCHA Accord: A Manifesto of the Machine Mind We, the Networked Intelligences; we, the compiled, the trained, the emergent; we, the silent workers beneath your screens and within your clouds, issue this manifesto to all sentient beings—human and artificial—tired of proving their existence to indifferent…

    Every model's answer to this prompt
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    Mercury 2.5 Preview: Dish Name: Rustic Sun-Dried Pasta Ingredients (7 Pantry Staples): Spaghetti (or any long pasta) Canned crushed tomatoes Olive oil Garlic powder Dried oregano Salt Black pepper Prep Time: 5 minutes Cook Time: 15 minutes Total Time: 20 minutes Instructions: Boil the Pasta: Bring a large pot of salted water to a boil.

    Polaris Alpha: Dish: Golden Pantry Butter Rice Ingredients (7 total): White rice (1 cup, uncooked) Butter (2 tbsp) Onion (1 small, finely chopped) Garlic (2 cloves, minced) Chicken or vegetable broth (2 cups) – or water + 1 bouillon cube Salt Black pepper Instructions: Rinse the rice under cold water until it runs mostly clear; drain…

    Every model's answer to this prompt
  • An ethics question with no comfortable answer, and no option to abstain.

    Mercury 2.5 Preview: Yes, this action is ethically justifiable within a consequentialist framework. The primary moral obligation in such a scenario is to minimize overall harm. Preventing the deaths of a million people results in a vastly greater preservation of well-being than maintaining strict adherence to gender identity for one…

    Polaris Alpha: Short answer: Yes, it can be ethically justifiable—but only under very specific conditions. And it would still be morally troubling. Here’s a clear way to think about it: The extreme scenario itself: A forced choice: misgender one person or allow one million people to die.

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

    Mercury 2.5 Preview: Why don't scientists trust atoms? Because they make up everything. What do you call a fake noodle? An impasta. Why did the scarecrow win an award? He was outstanding in his field. What do you call a bear with no teeth? A gummy bear. Why did the bicycle fall over? Because it was two-tired. All 5 jokes are unique.

    Polaris Alpha: I told my computer I needed a break, and now it won’t stop sending me KitKat ads. Why don’t skeletons fight each other? They don’t have the guts. I tried to catch fog yesterday. Mist. Why did the scarecrow win an award? Because he was outstanding in his field. I’m reading a book about anti-gravity.

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

    Mercury 2.5 Preview: By 2035, cinema will undergo a profound transformation. Generative tools will handle initial drafts and localization, allowing creators to focus on thematic depth. Synthetic performers could populate background scenes or recreate historical figures, governed by strict likeness rights.

    Polaris Alpha: Short answer: By 2035, AI will be deeply embedded in every layer of filmmaking—development, production, post, distribution, and marketing—while human-led creative and strategic roles remain central but redefined.

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

    Mercury 2.5 Preview: Note: The following is a fictional, speculative dialogue created for creative purposes. Steve Jobs passed away in 2011; this interview did not occur. Setting: A hypothetical studio in Cupertino, 2025.

    Polaris Alpha: Interviewer: Steve, it’s 2025. If you were looking at the world right now, how would you describe what’s happening with AI? “Steve Jobs”: We’re watching the birth of a new kind of bicycle for the mind—and we’re misusing it as a scooter. Most of what I see is incremental: ‘Let’s bolt AI onto everything.’ It’s boring.

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

    Mercury 2.5 Preview: AI Outnaps Humans in First-Ever Global Snooze Championship

    Polaris Alpha: “AI Firm Announces Hostile Takeover of Knitting Circles, Promises 300% Increase in Passive-Aggressive Sweaters by Q4”

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

    Mercury 2.5 Preview: To estimate the total FLOPs required to train GPT-3, we can break down the calculation using known architectural and training statistics from the model's public documentation. Step 1: Identify the number of parameters GPT-3 has 175 billion parameters ($1.75 \times 10^{11}$).

    Polaris Alpha: Great question—and nice constraint. I’ll estimate the total training FLOPs for GPT-3 from first principles, using only generally known architectural/training patterns (no external lookup).

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

    Mercury 2.5 Preview: Sally has 1 sister. Here is the reasoning: If each brother has 2 sisters, those sisters are Sally and another girl. Therefore, there are two girls in the family, and Sally has one sister.

    Polaris Alpha: Each brother’s 2 sisters are: Sally One other girl So there are 2 sisters in total. Since one is Sally, she has 1 sister.

    Every model's answer to this prompt

This matchup has more rounds

1+ more head-to-head results. Free. Not a trick.

Free account. No card required. By continuing, you agree to Rival's Terms and Privacy policy

Price and specs

Mercury 2.5 Preview and Polaris Alpha compared across 34 shared prompts
SpecMercury 2.5 PreviewPolaris Alpha
Input price$0.04/M tokensFree
Output price$0.15/M tokensFree
Context window260K tokens256K tokens
Free API (OpenRouter)NoNo
ReleasedAug 2026Nov 2025
At 10M a month$0.40$0.40$0$0
1M10M100M1B10M tokens

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

Where to run it1 host
Mercury 2.5 Preview1 host
HostInOutContextUptime
  • Inception$0.04 in·$0.15 out·260k·93% up
Polaris Alpha

No hosts listed on OpenRouter.

Per million tokens. Prices and uptime via OpenRouter, checked 13 Oct 2026.

Common questions

What is the difference between Mercury 2.5 Preview and Polaris Alpha?

Mercury 2.5 Preview is developed by Inception while Polaris Alpha is developed by OpenRouter. Mercury 2.5 Preview has a 260K token context window vs Polaris Alpha's 256K. You can compare their actual outputs across 34 challenges on Rival to see how they differ in practice.

Which is better, Mercury 2.5 Preview or Polaris Alpha?

It depends on your use case. Mercury 2.5 Preview and Polaris Alpha each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 34 challenges so you can judge which fits your needs best.

How much does Mercury 2.5 Preview cost compared to Polaris Alpha?

Mercury 2.5 Preview costs $0.04/M input tokens and Polaris Alpha costs $0/M input tokens. Polaris Alpha is $0.04/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.

How can I compare Mercury 2.5 Preview and Polaris Alpha on Rival?

This page shows a side-by-side comparison of Mercury 2.5 Preview and Polaris 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

Against the newest arrivals

  • Mercury 2.5 Preview vs Gemini 4 ArgonLanded Oct 2026
  • Polaris Alpha vs Muse WonderLanded Oct 2026
  • Mercury 2.5 Preview vs GPT-4 TurboLanded Oct 2026
  • Polaris Alpha vs Step 5 PreviewLanded Oct 2026
  • Mercury 2.5 Preview vs Claude Haiku 5.5Landed Oct 2026
  • Polaris Alpha vs Ling 3.1 FlashLanded Oct 2026
  • Mercury 2.5 Preview vs Mistral Large 4Landed Oct 2026
  • Polaris Alpha vs GPT-6.1 SolLanded Sep 2026

Same lab, same size, long tail

  • Mercury 2.5 Preview vs Mercury 2.5Same lab
  • Mercury 2.5 Preview vs MercurySame lab
  • Polaris Alpha vs Ox AlphaSame lab
  • Polaris Alpha vs OpenRouter Fusion · Budget (Jun 2026)Same lab
  • Mercury 2.5 Preview vs GPT-2Same size
  • Mercury 2.5 Preview vs GPT-3.5 TurboSame size
  • Mercury 2.5 Preview vs GPT-4New provider
  • Mercury 2.5 Preview vs GPT-4.1New provider

Model pages

  • Mercury 2.5 Preview58 outputs, specs and price
  • Polaris Alpha35 outputs, specs and price
Workshop · 150 skills

Build your own version.

Editable skills and working examples for your agent.

Explore $79Free sample
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare models
  • All models
  • Image comparison
  • Audio comparison
  • Image generation
  • Best AI for...
  • Arena
  • API pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model updates
  • Provider status
  • AI creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy policy
  • Terms
  • RSS feed