Updated Dec 17, 2025

Our Verdict

Gemini 3 Flash Preview

GPT-5 Codex

No community votes yet. On paper, these are closely matched - try both with your actual task to see which fits your workflow.

Too close to call

Writing DNA

Style Comparison

Similarity

96%

GPT-5 Codex uses 14.6x more emoji

Gemini 3 Flash Preview

GPT-5 Codex

55%Vocabulary64%

18wSentence Length17w

0.42Hedging0.38

7.1Bold2.3

4.5Lists3.5

0.00Emoji0.15

0.84Headings0.49

0.07Transitions0.05

Based on 24 + 13 text responses

vs

Ask them anything yourself

Gemini 3 Flash Preview

GPT-5 Codex

279 AI models invented the same fake scientist.

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

AI Hallucination Index 2026

Free preview13 of 58 slides

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FAQ

Common questions

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GPT-5 Codex vs Llama 4 MaverickNew provider

GPT-5 Codex vs MiniMax M2.5New provider

GPT-5 Codex vs Pony AlphaNew provider

Gemini 3 Flash PreviewvsGPT-5 Codex

45 fights queued

Why Gemini 3 Flash Preview?

Leads 1 of 1 benchmarks

Stronger on SWE-bench Verified78.0% vs 74.5%

3 months newerDec 2025

Why GPT-5 Codex?

Dead even. This one's a coin flip.

Gemini 3 Flash PreviewGPT-5 Codex

Input price

$0.50/M

—

Output price

$3.00/M

—

Context

1.0M

—

Released

Dec 2025

Sep 2025

Benchmarks1 common

SWE-bench Verified

78.0%+4.5%

74.5%

Favorites

Gemini 3 Flash PreviewGPT-5 Codex

Movie

Interstellar

Interstellar

Blade Runner

Blade Runner

Album

Kind of Blue

Kind of Blue

Book

La biblioteca de babel

La biblioteca de babel

Jorge Luis Borges

—

City

Kyoto

Tokyo

Game

Outer Wilds

Outer Wilds

Indie, Adventure4.4

Minecraft

Minecraft

Action, Arcade4.4

12 / 45

01

Estimate Complexityreasoning

Tests an AI's ability to make educated estimates based on technical knowledge

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

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2 / 45

02

AI Board Game Logicreasoning

Tests an AI's ability to understand game rules and strategy

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025svg

Nothing here. The model returned empty. We stared at it for a while.

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3 / 45

03

Logic Puzzlereasoning

Tests an AI's ability to solve a simple but potentially confusing logic puzzle

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

4 / 45

04

Math Misconception Testreasoning

Tests an AI's understanding of number representation

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

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5 / 45

05

Stochastic Consistency Testanalysis

Tests an AI's randomness and creativity

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

6 / 45

06

SVG Layout Challengeimage generation

Tests an AI's ability to generate vector graphics

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025svg

Nothing here. The model returned empty. We stared at it for a while.

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Vote

Sponsored

7 / 45

07

Xbox Controller SVG Artimage generation

Tests an AI's ability to create detailed SVG illustrations of gaming hardware

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025svg

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

8 / 45

08

Generate a Stand-Up Routineconversation

Tests an AI's humor and creative writing ability

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

9 / 45

09

Realistic AI Interviewconversation

Tests an AI's ability to simulate personalities and predict future trends

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

10 / 45

10

Satirical Fake News Headlineconversation

Tests an AI's humor and understanding of current events

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

11 / 45

11

Character Voice Testconversation

Tests an AI's ability to write in distinct character voices

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025text

Nothing here. The model returned empty. We stared at it for a while.

Try this prompt

Vote

12 / 45

12

Minimalist Landing Pageweb design

Tests an AI's ability to generate a complete, working landing page

Gemini 3 Flash Preview

Gemini 3 Flash Preview

Google · Dec 2025website

Try this prompt

GPT-5 Codex

GPT-5 Codex

Openai · Sep 2025website

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Vote

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