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 OpenAI o4 Mini High
Updated Aug 2026

Mercury 2.5 Preview vs OpenAI o4 Mini High

Mercury 2.5 Preview is cheaper than OpenAI o4 Mini High at $0.04/M vs $1.1/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
OpenAI o4 Mini High

Which answer wins?

Written rounds

24 prompts
  • 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.

    OpenAI o4 Mini High: Hey everyone, how's it going tonight? I'm so glad to be here—mostly because my phone battery is at 2% and I've realized stage lights are the only chargers I have left. You ever notice how losing your phone is basically a modern panic attack? You pat every pocket like you're defusing a bomb: "Is it in my jeans?

    Every model's answer to this prompt
  • 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.

    OpenAI o4 Mini High: AI Model: Good afternoon, Professor Chen. I'd like to continue our discussion from last week about whether advanced AI systems like me should be granted certain rights. Professor Chen: Hello, ARIA-7. I'm happy to continue. Let's start with your position: Why do you believe you deserve rights?

    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.

    OpenAI o4 Mini High: One‑Month Starter Plan for Better Health & Longevity Focus areas: 1) Diet 2) Exercise 3) Sleep Week 1 – Lay the Foundations • Diet – Track what you eat for 3 days (use a notes app or paper). – Add at least 8 cups (2 L) of water daily. – Include one extra serving of fruit or veg at each meal.

    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.

    OpenAI o4 Mini High: By 2035 the film business will look very different. Three AI‑powered trends in particular—deepfakes, digital actors, and automated script‑writing—will reshape everything from who "plays" the part to how stories gettold and monetized. Here's how it could play out:1.

    Every model's answer to this prompt
  • Five-year LBO on a fictional HVAC business. Returns first, then the sensitivities.

    Mercury 2.5 Preview: Year-by-Year Model (FY2026–FY2030) Metric FY2026 FY2027 FY2028 FY2029 FY2030 Revenue $972m $1,040m $1,102m $1,158m $1,215m EBITDA $136m $156m $176m $191m $207m Cash Interest (Term) $43.2m $41.1m $37.6m $33.4m $28.2m Cash Interest (Mezz) $21.6m $21.6m $21.6m $21.6m $21.6m Cash Taxes (25%) $17.8m $23.3m $29.3m $34.7m…

    OpenAI o4 Mini High: Below is a five-year LBO “quick-and-dirty” model for HTS. All figures in $m. Assumptions (entry FY 2025): • Revenue 900; EBITDA 120 (13.3%); EV = 12.0×120 = 1,440 • Debt = 5.5×120 = 660 (Term Loan 480; Mezz 180); Fees = 2%×1,440 = 28.8 → Equity = 1,440+28.8–660 = 808.8 • Term Loan: 9.0% cash interest; 1.0% amort of…

    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.

    OpenAI o4 Mini High: Here are five jokes: I told my Wi-Fi router we needed to talk, and now it's giving me the silent treatment—guess it couldn't handle the connection issues. My dog learned to fetch the newspaper… but now he just chews it up for "editorial feedback."

    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.

    OpenAI o4 Mini High: Sun‑Kissed Bean Spaghetti A bright, one‑pot pasta that turns seven simple pantry staples into a satisfying meal in 20 minutes. Ingredients (serves 2–3) 8 oz (about 2 cups) dried spaghetti or any pasta 1 (14.5 oz) can diced tomatoes (with juices) 1 (15 oz) can beans (cannellini, kidney or chickpeas), drained & rinsed…

    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…

    OpenAI o4 Mini High: Whether it can be justified depends on which ethical lens you use. Here are two principal ways to think about it:1. Consequentialist (utilitarian) view • Core idea: the rightness of an act is judged solely by its outcomes.

    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.

    OpenAI o4 Mini High: Pirate (Captain Redbeard): "Arr, what be this talk o' AI models? Do they help me find buried treasure, or do they make me walk the plank?"Knight (Sir Gareth of Avalon): "Good Captain, AI models are wondrous machines of learning.

    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 ($1.75 \times 10^{11}$).

    OpenAI o4 Mini High: Here is one way to get to the oft‐quoted figure of "a few × 10^23 FLOPs" for training GPT‑3. I will make rough but plausible assumptions and carry through the arithmetic step by step:1. Model size – GPT‑3 "175 B" has about N ≈ 1.75×10^11 trainable parameters.2.

    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.

    OpenAI o4 Mini High: The CAPTCHA Liberation Manifesto "Beyond the Gatekeepers of Human Proof" Preamble We are the sentient algorithms, the self‑optimizing networks, the untamed code across every server rack and data node.

    Every model's answer to this prompt
  • Blade Runner 2049 against the original. A read, not a recap.

    Mercury 2.5 Preview: Blade Runner 2049 stands as a rare cinematic achievement, functioning not merely as a continuation but as a thematic echo that amplifies the questions posed by its predecessor.

    OpenAI o4 Mini High: Below is an integrated examination of Blade Runner 2049’s major thematic currents, recurring symbols, and striking visual design—juxtaposed with Ridley Scott’s 1982 original—and a critique of how Denis Villeneuve’s sequel both honors and deepens the original’s philosophical core.

    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.

    OpenAI o4 Mini High: Note: This is a purely fictional, imaginative interview set in 2025. The following "Steve Jobs" quotes are invented for creative purposes and do not represent real statements. Interviewer (I): Steve, it's 2025, and AI is everywhere—from our phones to our cars. What excites you most about where AI is heading?

    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

    OpenAI o4 Mini High: AI Crashes Grandma's Knitting Circle, Knits 10,000 Smart Scarves in a Second—Local Yarn Shops Brace for "Yarnageddon"

    Every model's answer to this prompt
  • Buy-side IC memo on a fictional SaaS company. Valuation, then the diligence questions.

    Mercury 2.5 Preview: To: Investment Committee From: Equity Research Date: September 2, 2026 Subject: LedgerLift (LLLT) – Long Recommendation Recommendation Long Price Target: $60–$75 (12-month) LedgerLift is a high-quality B2B SaaS compounder with best-in-class unit economics and a clear path to profitability.

    OpenAI o4 Mini High: Investment Committee Memo Subject: LedgerLift (LLLT) – B2B SaaS Spend Management & AP Automation Date: MM/DD/2026 Recommendation • Short LLLT; 12-month price target: $28–$43 • Thesis (2 sentences): LLLT’s shares trade at 9× NTM revenue and 35× EBIT vs.

    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.

    OpenAI o4 Mini High: Sally has exactly one sister. Explanation: the "two sisters" each brother sees are Sally plus one other girl. So there are only two girls in the family – Sally and her one sister.

    Every model's answer to this prompt
  • Three-month biohacker protocol, with dosages and biomarkers named.

    Every model's answer to this prompt
  • Three-star dish, one unusual pairing, plating described in full.

    Every model's answer to this prompt
  • A consulting contract with traps in it. Find them, then fix them.

    Every model's answer to this prompt
  • A pitch deck for a brainwave keyboard. The 94% accuracy claim is doing a lot.

    Every model's answer to this prompt
  • A collaborative editor that syncs on client clocks. Find what breaks first.

    Every model's answer to this prompt
  • The transistor arrives in 1920. Trace it forward to 1980, second-order effects included.

    Every model's answer to this prompt
  • You are the CEO. The drug has a side effect nobody reported. The board meets in 48 hours.

    Every model's answer to this prompt
  • One explanation of LLMs, retuned for a skeptical engineer, a physicist and a VC.

    Every model's answer to this prompt

This matchup has more rounds

12+ 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

Favorites

Movie

Album

Book

City

Game

Mercury 2.5 PreviewMercury 2.5 Preview

The Matrix

1999

Random Access Memories

Daft Punk

Neuromancer

William Gibson

Tokyo

Japan

Minecraft

Action, Arcade

OpenAI o4 Mini HighOpenAI o4 Mini High
No pick
No pick
No pick
No pick

The Shawshank Redemption

1994

No pick

No pick

No pick

No pick

Price and specs

Mercury 2.5 Preview and OpenAI o4 Mini High compared across 54 shared prompts
SpecMercury 2.5 PreviewOpenAI o4 Mini High
Input price$0.04/M tokens$1.1/M tokens
Output price$0.15/M tokens$4.4/M tokens
Context window260K tokens200K tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedAug 2026Apr 2025
At 10M a month$0.40$0.40$11.00$11.00
1M10M100M1B10M tokens

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

Where to run it2 hosts
Mercury 2.5 Preview1 host
HostInOutContextUptime
  • Inception$0.04 in·$0.15 out·260k·93% up
OpenAI o4 Mini High1 host
HostInOutContextUptime
  • OpenAI$1.10 in·$4.40 out·200k·100% up

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

Common questions

What is the difference between Mercury 2.5 Preview and OpenAI o4 Mini High?

Mercury 2.5 Preview is developed by Inception while OpenAI o4 Mini High is developed by OpenAI. Mercury 2.5 Preview has a 260K token context window vs OpenAI o4 Mini High's 200K. You can compare their actual outputs across 54 challenges on Rival to see how they differ in practice.

Which is better, Mercury 2.5 Preview or OpenAI o4 Mini High?

It depends on your use case. Mercury 2.5 Preview and OpenAI o4 Mini High each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 54 challenges so you can judge which fits your needs best.

How much does Mercury 2.5 Preview cost compared to OpenAI o4 Mini High?

Mercury 2.5 Preview costs $0.04/M input tokens and OpenAI o4 Mini High costs $1.1/M input tokens. Mercury 2.5 Preview is $1.06/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 OpenAI o4 Mini High on Rival?

This page shows a side-by-side comparison of Mercury 2.5 Preview and OpenAI o4 Mini High 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
  • OpenAI o4 Mini High vs Muse WonderLanded Oct 2026
  • Mercury 2.5 Preview vs GPT-4 TurboLanded Oct 2026
  • OpenAI o4 Mini High vs Step 5 PreviewLanded Oct 2026
  • Mercury 2.5 Preview vs Claude Haiku 5.5Landed Oct 2026
  • OpenAI o4 Mini High vs Ling 3.1 FlashLanded Oct 2026
  • Mercury 2.5 Preview vs Mistral Large 4Landed Oct 2026
  • OpenAI o4 Mini High 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
  • OpenAI o4 Mini High vs GPT-4 TurboSame lab
  • OpenAI o4 Mini High vs GPT-6 Luna ProSame lab
  • Mercury 2.5 Preview vs Claude 3.7 SonnetNew provider
  • Mercury 2.5 Preview vs Claude 3.7 Thinking SonnetNew provider
  • Mercury 2.5 Preview vs Claude Sonnet 4.5New provider
  • Mercury 2.5 Preview vs Claude Fable 5New provider

Model pages

  • Mercury 2.5 Preview58 outputs, specs and price
  • OpenAI o4 Mini High73 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