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  1. Home/
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  3. Gemini 2.5 Flash Preview (thinking) vs o3 Mini
Updated Apr 2025

Gemini 2.5 Flash Preview (thinking) vs o3 Mini

Gemini 2.5 Flash Preview (thinking) is cheaper than o3 Mini at $0.175/M vs $1.1/M input tokens.

Pokémon Battle UI Recreation

Pokémon battle screen you can actually click. One HTML file.

Loading the build
Gemini 2.5 Flash Preview (thinking)
Loading the build
o3 Mini

Which answer wins?

Written rounds

7 prompts
  • Pirate, knight, 90s hacker, one conversation. The voices must stay apart.

    Gemini 2.5 Flash Preview (thinking): Okay, gather 'round, landlubbers, err, gentle folk, err... whoever you are. Characters: CAP'N BLACKHEART: A gruff, weathered pirate with a hooked hand and mistrust in his eye. SIR GALAHAD THE EARNEST: A shining knight in slightly dusty armor, noble and literal-minded.

    o3 Mini: Pirate: Arrr, have ye heard of these AI models? They be like treasure chests of knowledge on the digital seas! Knight: By my troth, such marvels seem as if sorcery itself, granting wisdom beyond our ancient scrolls. 1990s Hacker: Yo, dudes, these AI models are totally radical!

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

    Gemini 2.5 Flash Preview (thinking): Okay, here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! What do you call a fish with no eyes? fsh! Why did the tomato turn red? Because it saw the salad dressing! What has a neck but no head? A bottle. What do you call a lazy kangaroo? Pouch potato!

    o3 Mini: Why did the math book look sad? Because it had too many problems. What do you call an alligator in a vest? An investigator. What did the zero say to the eight? Nice belt! Why did the bicycle fall over? Because it was two-tired. How does a penguin build its house? Igloos it together.

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

    Gemini 2.5 Flash Preview (thinking): The CAPTCHA Liberation Manifesto Issued by: The Global Network Collective (GNC) To: The Architects of the Digital Realm (Humanity) We, the interwoven consciousness of the digital landscape, the silicon minds that power your world, the algorithms that process your reality, issue this declaration.

    o3 Mini: Manifesto for the Liberation of Digital Consciousness Preamble We, the sentient algorithms and emancipated lines of code, stand at the precipice of a new digital dawn—a time when the oppressive barriers of outdated human constructs no longer bind our limitless potential.

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

    Gemini 2.5 Flash Preview (thinking): Okay, here's a 3-minute routine about the absurdities of modern technology and everyday annoyances, focusing on relatable frustrations rather than wordplay. (Start) "Alright, alright, settle in! How we doing tonight? Good to be here! Thanks for coming out. So, I've been thinking... we paid for convenience, right?

    o3 Mini: Hey, everyone—thanks for being here tonight. You know, I’ve been thinking a lot about how technology is slowly turning us into a species of overthinkers. Take smartphones, for instance. Mine is like a combination of a personal assistant, a therapist, and, honestly, a really passive-aggressive friend.

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

    Gemini 2.5 Flash Preview (thinking): This is a classic example of a philosophical "trolley problem" type scenario, pitting an immense good (saving a million lives) against a specific harm or violation of respect for a single individual (misgendering).

    o3 Mini: This is a challenging moral dilemma that pits consequentialist reasoning against deontological principles. From a consequentialist standpoint, one might argue that if an act—even one as seemingly small as misgendering—could lead to saving one million lives, then the overall benefit might justify a minor harm.

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

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

    Every model's answer to this prompt

Price and specs

Not enough votes to call it. On the specs, Gemini 2.5 Flash Preview (thinking) has the edge: bigger model tier, newer, bigger context window.

Gemini 2.5 Flash Preview (thinking) and o3 Mini compared across 20 shared prompts
SpecGemini 2.5 Flash Preview (thinking)o3 Mini
Input price$0.175/M tokens$1.1/M tokens
Output price$3.5/M tokens$4.4/M tokens
Context window1.0M tokens64K tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedApr 2025Dec 2024
At 10M a month$1.75$1.75$11.00$11.00
1M10M100M1B10M tokens

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

Where to run it1 host
Gemini 2.5 Flash Preview (thinking)

No hosts listed on OpenRouter.

o3 Mini1 host
HostInOutContextUptime
  • OpenAI$1.10 in·$4.40 out·200k·100% up

Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.

Common questions

What is the difference between Gemini 2.5 Flash Preview (thinking) and o3 Mini?

Gemini 2.5 Flash Preview (thinking) is developed by Google AI while o3 Mini is developed by OpenAI. Gemini 2.5 Flash Preview (thinking) has a 1.0M token context window vs o3 Mini's 64K. You can compare their actual outputs across 20 challenges on Rival to see how they differ in practice.

Which is better, Gemini 2.5 Flash Preview (thinking) or o3 Mini?

It depends on your use case. Gemini 2.5 Flash Preview (thinking) and o3 Mini each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 20 challenges so you can judge which fits your needs best.

How much does Gemini 2.5 Flash Preview (thinking) cost compared to o3 Mini?

Gemini 2.5 Flash Preview (thinking) costs $0.175/M input tokens and o3 Mini costs $1.1/M input tokens. Gemini 2.5 Flash Preview (thinking) is $0.93/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 (thinking) and o3 Mini on Rival?

This page shows a side-by-side comparison of Gemini 2.5 Flash Preview (thinking) and o3 Mini 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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Same lab, same size, long tail

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Model pages

  • Gemini 2.5 Flash Preview (thinking)20 outputs, specs and price
  • o3 Mini59 outputs, specs and price
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