What is the difference between GPT-5.1 and Gemini 2.5 Pro (I/O Edition)?

GPT-5.1 is developed by OpenAI while Gemini 2.5 Pro (I/O Edition) is developed by Google AI. in 21 community votes on Rival, Gemini 2.5 Pro (I/O Edition) wins 62% of head-to-head matchups. These results are based on blind head-to-head voting across 35 challenges.

Which is better, GPT-5.1 or Gemini 2.5 Pro (I/O Edition)?

Based on 21 community votes on Rival, Gemini 2.5 Pro (I/O Edition) wins 62% of head-to-head matchups against GPT-5.1. Gemini 2.5 Pro (I/O Edition) is strongest in Reasoning, Web Design.

How much does GPT-5.1 cost compared to Gemini 2.5 Pro (I/O Edition)?

GPT-5.1 costs $1.25/M input tokens and Gemini 2.5 Pro (I/O Edition) costs $1.25/M input tokens. Gemini 2.5 Pro (I/O Edition) is $0.00/M cheaper per input. Gemini 2.5 Pro (I/O Edition) also wins more often in community votes, making it the better value.

How are GPT-5.1 vs Gemini 2.5 Pro (I/O Edition) votes collected on Rival?

Rival presents both models' outputs side-by-side in blind duels. Voters see the responses but don't know which model produced each one, eliminating brand bias. 21 votes have been collected for this pair across 35 challenges. All vote data is part of Rival's open dataset.

GPT-5.1 vs Gemini 2.5 Pro (I/O Edition): Which Is Better? [2026 Comparison]

Rival

Updated Nov 13, 2025

Our Verdict

Gemini 2.5 Pro (I/O Edition)Winner

GPT-5.1Runner-up

Pick Gemini 2.5 Pro (I/O Edition). In 21 blind votes, Gemini 2.5 Pro (I/O Edition) wins 62% of the time. That's not luck.

Gemini 2.5 Pro (I/O Edition) particularly excels in Web Design, Reasoning.

Clear winner

Writing DNA

Style Comparison

Similarity

97%

GPT-5.1 uses 2.3x more transitions

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

62%Vocabulary58%

19wSentence Length16w

0.29Hedging0.38

3.5Bold5.8

7.2Lists5.0

0.00Emoji0.00

0.61Headings0.63

0.03Transitions0.01

Based on 14 + 16 text responses

Ask them anything yourself

279 AI models invented the same fake scientist.

We read every word. 250 models. 2.14 million words. This is what we found.

Free preview13 of 58 slides

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FAQ

Common questions

Keep going

GPT-5.1 vs Grok 3New provider

GPT-5.1 vs Llama 4 MaverickNew provider

GPT-5.1 vs Claude Opus 4New provider

So I’m trying to be a better person, which in 2025 just means I bought a water bottle the size of a toddler. That’s the whole self-improvement plan. It’s not therapy, it’s not reading books. It’s, “If I drink 3 of these, I’m emotionally stable.”

I walk around with this thing like I’m on a hike… in my own apartment. I can’t even sit on the couch without planning a route. I’m like, “Okay, I’ll leave the kitchen at 0900, hit the couch by 0903, water check at 0915, bathroom at 0920, we move as a team, people.”

And every bottle has those inspirational markings on the side now: “9 AM: You’ve got this!” “11 AM: Keep going!” “1 PM: Almost there!” By 3 PM I’m like, “I have done nothing today… except pee 19 times. This bottle is my only coworker. And it’s passive-aggressive.”

I miss when water was just… around. You were thirsty, you drank from a sink like a raccoon. Now if I drink from a faucet people look at me like I just licked a subway pole. “Are you okay? Do you need help? Blink twice if you need a reusable straw.”

I’m also trying to be “mindful.” That’s the new thing. Every app wants you to breathe. I open my phone: notifications, emails, one app’s like, “Have you taken 10 deep breaths today?” I’m like, “No, I’ve been holding my breath since 2016.”

So I downloaded a meditation app. It has this calm voice like, “Notice your thoughts… and let them go.” But my thoughts are like, “Did you pay your taxes? Did you hit reply all? Is your boss mad?” And the app’s like, “Let them float away like clouds.” I’m like, “No, these are thunderstorms. These thoughts have property damage.”

And the app gives me streaks. “You’ve meditated for 3 days in a row!” No I haven’t, I just opened the app and panicked. That shouldn’t count. That’s like saying, “You’ve gone to the gym 5 days in a row!” No, I drove past it in traffic and remembered I’m weak.

Speaking of gyms, why is every gym either a nightclub or a warehouse? It’s either purple lights, DJ in the corner, everyone looks like an action figure… or it’s some cross-training dungeon where tires hang from the ceiling and someone’s flipping a tractor in the background.

I just want a normal place where I can lift something light, breathe loudly, and not be judged by a 19-year-old trainer named Brayden whose entire job is to yell “Let’s go!” while never sweating. He’s walking around in a tank top like a motivational seagull. “Let’s go! One more! You got this!” Sir, you are holding a clipboard. You have not “got” anything.

Even grocery shopping is intense now. There’s a self-checkout, a regular checkout, a fifteen-items-or-less lane, a “drive up” lane, and then the lane for people who remembered their reusable bags and their morals. I always end up in the wrong one. I’ll stand in self-checkout with 40 items, trying to scan broccoli like it’s a DVD.

The machine is never chill. It’s always yelling, “Unknown item in bagging area!” It’s broccoli. It’s the most known item in the bagging area. Meanwhile, the human cashier is just watching, like, “You chose this, champ. You wanted to live in the future.”

Anyway, I gotta go drink three more gallons of water, breathe on purpose, pretend driving past the gym is exercise, and argue with a robot about produce. I think I’m nailing adulthood.

GPT-5.1 vs Gemini 2.5 Pro (I/O Edition)

Which is better, GPT-5.1 or Gemini 2.5 Pro (I/O Edition)?

Key Differences Between GPT-5.1 and Gemini 2.5 Pro (I/O Edition)

Style Comparison

Common questions

What is the difference between GPT-5.1 and Gemini 2.5 Pro (I/O Edition)?

Which is better, GPT-5.1 or Gemini 2.5 Pro (I/O Edition)?

How much does GPT-5.1 cost compared to Gemini 2.5 Pro (I/O Edition)?

How are GPT-5.1 vs Gemini 2.5 Pro (I/O Edition) votes collected on Rival?

Why GPT-5.1?

Why Gemini 2.5 Pro (I/O Edition)?

Favorites

Estimate Complexityreasoning

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Logic Puzzlereasoning

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Math Misconception Testreasoning

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Stochastic Consistency Testanalysis

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

SVG Layout Challengeimage generation

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Xbox Controller SVG Artimage generation

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Generate a Stand-Up Routineconversation

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Realistic AI Interviewconversation

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Satirical Fake News Headlineconversation

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Minimalist Landing Pageweb design

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Pokémon Battle UI Recreationweb design

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

Mario Level UI Recreationweb design

GPT-5.1

Gemini 2.5 Pro (I/O Edition)

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