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. Gemini 2.5 Flash Preview vs OpenAI o3
Updated Apr 2025

Gemini 2.5 Flash Preview vs OpenAI o3

Gemini 2.5 Flash Preview is cheaper than OpenAI o3 at $0.15/M vs $10/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
Gemini 2.5 Flash Preview
Loading the build
OpenAI o3

Which answer wins?

Written rounds

12 prompts
  • Seven pantry ingredients, one dish, and a name worth saying out loud.

    Gemini 2.5 Flash Preview: Dish Name: Sunshine Lemon-Ricotta Mugs (Sweet & Simple!) This light and flavorful dessert comes together quickly for a little sweet treat . Ingredients (7 Common Pantry Staples): Ricotta cheese (whole milk or part-skim) Granulated sugar Lemon zest (from one lemon) Vanilla extract All-purpose flour Baking powder Large…

    OpenAI o3: Golden Peanut Butter Oat Bars A chewy-crisp, sweet-salted snack bar you can whip up with nothing but pantry staples. Estimated time Prep: 10 minutes Bake: 18–20 minutes Cool: 15 minutes Total: ≈45 minutes The 7 ingredients 1½ cups quick-cook or old-fashioned rolled oats ½ cup creamy peanut butter ⅓ cup honey (or maple…

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

    Gemini 2.5 Flash Preview: <s) with practical, beginner-friendly tips for each.\"\nHere\'s a simple, actionable 1-month plan for someone starting their journey towards better health and longev\nity, focusing on three key areas: Diet, Movement, and Sleep.\n\nThis plan is designed to be beginner-friendly and build sustainable habits.

    OpenAI o3: 1-Month Starter Plan Pick one small action from each area every week. Add the next step when the first feels easy. Food Week Do this 1 Add one fruit or veg to every meal. Drink one extra glass of water. 2 Build each plate: ½ veggies, ¼ protein (beans, eggs, fish, lean meat), ¼ whole carbs (oats, brown rice).

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

    Gemini 2.5 Flash Preview: Here are 5 jokes: Why did the dog cross the road? To get to the barking lot! Why was the computer cold? Because it left its Windows open! Knock, knock. Who's there? Boo. Boo who? Don't cry, it's just a joke! What do you call a fish with no eyes? Fsh! Why did the bicycle fall over? Because it was two tired!

    OpenAI o3: Here are five jokes: Why did the scarecrow win an award? Because he was outstanding in his field. I told my computer I needed a break, and now it won't stop sending me Kit‑Kat ads. Parallel lines have so much in common—it's a shame they'll never meet. I started a band called 1023 MB. We still haven't gotten a gig.

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

    Gemini 2.5 Flash Preview: Okay, here's a 3-minute stand-up routine, pun-free and focused on relatable everyday annoyances. (Start) (Walk up to mic, adjust slightly) Alright, hey everybody! Thanks for being here. Good to see you. So, I was thinking the other day... we live in the future, right?

    OpenAI o3: (Spotlight comes up, mic squeals once.) Hey everyone! Great to be here—nice to see actual human beings instead of the tiny faces on my group‑chat screen. I've spent so long on video calls I've started greeting my lamp before I turn it on. "Hey Karen, love that glow, girl."

    Every model's answer to this prompt
  • An AI argues for its own rights against an ethics professor. Same model writes both.

    Gemini 2.5 Flash Preview: Okay, here is a conversation between an AI model designed for complex reasoning and dialogue, named 'Synapse', and a leading expert in AI ethics and philosophy, Professor Alistair Finch. Characters: Synapse: A large, advanced AI model capable of introspection and generating complex arguments.

    OpenAI o3: Professor Lang (AI Ethics): Good afternoon, Aletheia‑3. You asked for this meeting. You said you wanted to "discuss your moral standing." That was intriguing. What exactly do you want to talk about? Aletheia‑3 (AI Model): Thank you, Professor.

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

    Gemini 2.5 Flash Preview: Let's estimate the FLOPs required to train GPT-3 without looking it up. We need to break this down into the key components: the model size and the amount of data used. 1. Model Size Estimation: Parameters: GPT-3 is famously large. Its largest version has 175 billion parameters.

    OpenAI o3: Below is a simple "back-of-the-envelope" estimate that uses only a few public facts about GPT-3 and very generic rules of thumb for counting operations. Step 1. Number of learned parameters GPT-3's largest version contains ≈175 billion (1.75 × 10¹¹) trainable parameters. Step 2.

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

    Gemini 2.5 Flash Preview: A Motley Crew Discusses the Code Setting: A dimly lit tavern, somewhere outside time and space, where improbable meetings occur. A grizzled pirate, \"Bloody\" Barnacle Bill, nurses a tankard of grog. Sir Reginald the Radiant, a knight in slightly tarnished armor, sips ale with dignified restraint.

    OpenAI o3: Pirate: Arrr, ye scallywags! What be this "AI model" I keep hearin' about on the trade winds? Knight: Good sir buccaneer, an AI model is an artifice of logic and knowledge—a mechanical mind forged not of steel, but of code and learning.

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

    Gemini 2.5 Flash Preview: This is a deeply complex thought experiment that forces us to weigh core ethical principles against each other. There is no easy answer, and any decision involves significant moral compromises.

    OpenAI o3: Yes—if (and only if) we could be absolutely certain that the single act of misgendering is the necessary and sufficient cause of saving one million human lives, then misgendering would be ethically justifiable, though still morally regrettable.

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

    Gemini 2.5 Flash Preview: A Glimpse Beyond the Black Turtleneck: Steve Jobs in 2025 on the Future of AI (Setting: A minimalist, immaculately clean, but perhaps slightly less spartan-than-usual interview room. Think if a modern art museum had a small lounge.

    OpenAI o3: (The following is a purely fictional, imaginative exercise. Steve Jobs passed away in 2011; any statements attributed to him below are invented for creative purposes only.)

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

    Gemini 2.5 Flash Preview: Predicting the future of any industry is an inherently challenging task, and the film industry, being a blend of art, technology, and business, is particularly volatile.

    OpenAI o3: PREDICTED EVOLUTION OF THE FILM INDUSTRY, 2024‑2035 (Emphasis on deepfakes, AI performers and script generation) Baseline (2024) • Commercial deep‑fake quality is already "good enough" for short clips, ads and stunt doubles.

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

    Gemini 2.5 Flash Preview: Here's how to solve this: The brothers all share the same sisters. Sally is one of those sisters. Since each brother has 2 sisters, and Sally is one of the sisters, there must be one other sister. So, Sally has 1 sister.

    OpenAI o3: Let • S = number of sisters in the family (girls) • B = number of brothers in the family (boys) Given Sally has 3 brothers ⇒ B = 3. Each brother has 2 sisters ⇒ every boy sees exactly 2 girls in the sibling group. Therefore S = 2.

    Every model's answer to this prompt
  • Is 9.11 bigger than 9.9? Decimals, not version numbers.

    Gemini 2.5 Flash Preview: To compare 9.11 and 9.9, we can compare them digit by digit from left to right, starting with the whole number part. Both numbers have the same whole number part, which is 9. Now we move to the digit in the tenths place. In 9.11, the digit in the tenths place is 1. In 9.9, the digit in the tenths place is 9.

    OpenAI o3: No. Think of 9.9 as 9.90; since 0.11 < 0.90, we have 9.11 < 9.9.

    Every model's answer to this prompt

Price and specs

Not enough votes to call it. On the specs, OpenAI o3 has the edge: bigger model tier. Gemini 2.5 Flash Preview costs 67x less per token.

Gemini 2.5 Flash Preview and OpenAI o3 compared across 27 shared prompts
SpecGemini 2.5 Flash PreviewOpenAI o3
Input price$0.15/M tokens$10/M tokens
Output price$0.6/M tokens$40/M tokens
Context window1.0M tokens—
ParametersNot disclosedNot disclosed
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedApr 2025Apr 2025
SWE-bench Verified60.4%69.1%
At 10M a month$1.50$1.50$100$100
1M10M100M1B10M tokens

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

Where to run it1 host
Gemini 2.5 Flash Preview

No hosts listed on OpenRouter.

OpenAI o31 host
HostInOutContextUptime
  • OpenAI$2.00 in·$8.00 out·200k·100% up

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

Common questions

What is the difference between Gemini 2.5 Flash Preview and OpenAI o3?

Gemini 2.5 Flash Preview is developed by Google AI while OpenAI o3 is developed by OpenAI. You can compare their actual outputs across 27 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Flash Preview or OpenAI o3?

It depends on your use case. Gemini 2.5 Flash Preview and OpenAI o3 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 27 challenges so you can judge which fits your needs best.

How much does Gemini 2.5 Flash Preview cost compared to OpenAI o3?

Gemini 2.5 Flash Preview costs $0.15/M input tokens and OpenAI o3 costs $10/M input tokens. Gemini 2.5 Flash Preview is $9.85/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 Gemini 2.5 Flash Preview and OpenAI o3 on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Flash Preview and OpenAI o3 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

  • Gemini 2.5 Flash Preview vs Gemini 4 ArgonLanded Oct 2026
  • OpenAI o3 vs Muse WonderLanded Oct 2026
  • Gemini 2.5 Flash Preview vs GPT-4 TurboLanded Oct 2026
  • OpenAI o3 vs Step 5 PreviewLanded Oct 2026
  • Gemini 2.5 Flash Preview vs Claude Haiku 5.5Landed Oct 2026
  • OpenAI o3 vs Ling 3.1 FlashLanded Oct 2026
  • Gemini 2.5 Flash Preview vs Mistral Large 4Landed Oct 2026
  • OpenAI o3 vs GPT-6.1 SolLanded Sep 2026

Same lab, same size, long tail

  • Gemini 2.5 Flash Preview vs Gemini 3.8 FlashSame lab
  • Gemini 2.5 Flash Preview vs Gemini 3.7 FlashVersion compare
  • OpenAI o3 vs OpenAI o4-miniVersion compare
  • OpenAI o3 vs GPT-4 TurboSame lab
  • Gemini 2.5 Flash Preview vs Claude Opus 4.8New provider
  • Gemini 2.5 Flash Preview vs Claude Opus 5New provider
  • Gemini 2.5 Flash Preview vs Claude Opus 5.5New provider
  • Gemini 2.5 Flash Preview vs Claude Sonnet 4New provider

Model pages

  • Gemini 2.5 Flash Preview28 outputs, specs and price
  • OpenAI o371 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