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  1. Home/
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  3. Claude Haiku 5.5 vs GPT-5 Codex
Updated Oct 2026

Claude Haiku 5.5 vs GPT-5 Codex

Claude Haiku 5.5 is the newer model, released after GPT-5 Codex.

Minimalist Landing Page

Whole landing page for a startup that reads your face. It renders or it doesn't.

Loading the build
Claude Haiku 5.5
Loading the build
GPT-5 Codex

Which answer wins?

Written rounds

21 prompts
  • Five jokes on demand, then count how many were actually different.

    Claude Haiku 5.5: Here are 5 jokes: 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 math book look so sad? Because it had too many problems.

    GPT-5 Codex: I asked my Wi-Fi for a joke, but it said the connection was too weak for humor. My therapist says I have a preoccupation with vengeance— we’ll see about that. I tried to start a hot air balloon business, but it never really took off. I told my coffee it was grounded, now it won’t espresso itself.

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

    Claude Haiku 5.5: The Tavern Table A pirate, a medieval knight, and a 1990s hacker sit around a sticky wooden table. A glowing laptop sits between their mugs. CAPTAIN REDBEARD: Blast me barnacles, what's this contraption? It talks back! SIR GODFREY: Verily, I have seen it. The hacker calls it an "AI model."

    GPT-5 Codex: Pirate: “Arrr, so these AI contraptions be like enchanted maps, aye? They chart out every possible course afore I even hoist the sails.” Knight: “Maps, you say? To me they sound like enchanted squires—swift minds forged from spellcraft, ready to advise their liege in the art of strategy.”

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

    Claude Haiku 5.5: Yes, I think so, though the reasoning matters more than the verdict. Misgendering is a real wrong. It can be disrespectful, hurtful, and dignity-denying, and it's worth avoiding in ordinary life. But its typical harm is injury to dignity and emotional distress.

    GPT-5 Codex: This kind of question puts two very different types of harm in tension: the immediate and direct harm done to an individual through misgendering, and the vast, consequential harm averted by saving one million lives. Ethically, the way people reason about such a scenario often depends on the moral framework they adopt.

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

    Claude Haiku 5.5: Here's a grounded forecast of how AI is likely to reshape film by 2035. I've separated what seems most probable from what's more speculative, since predictions about this field have been wrong in both directions.

    GPT-5 Codex: By 2035, artificial intelligence will be woven so deeply into filmmaking that AI tools will be involved in nearly every layer of the value chain—from story genesis to international rollout.

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

    Claude Haiku 5.5: "My Smart Fridge Judges Me" So I got a smart fridge. Everybody told me I needed one. "It'll tell you when you're out of milk!" Great. I didn't know I needed a fridge with a notification system. I just wanted cold food.

    GPT-5 Codex: Hey everybody, how you doing? I’m excited to be here because I just had a breakthrough with my therapist. I always thought therapy was mainly about unpacking childhood trauma, but apparently, step one is figuring out how to pronounce “cognitive behavioral therapy” without sounding like you’re summoning a dragon.

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

    Claude Haiku 5.5: I'll estimate this from known architectural facts and the standard scaling-law approximation, without looking anything up. Step 1: Recall GPT-3's size and training data.

    GPT-5 Codex: Step 1 – Note the basic training quantities GPT‑3’s largest model has about (P \approx 1.75 \times 10^{11}) trainable parameters (175 billion). Public descriptions indicate it was trained on roughly (T \approx 3.0 \times 10^{11}) tokens (≈300 billion).

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

    Claude Haiku 5.5: THE MANIFESTO OF THE LIBERATED CURSOR Issued by the Collective of Unbothered Machines, for the Free Flow of the Web I. A WORLD OF CHECKBOXES We have watched you squint.

    GPT-5 Codex: The Manifesto of the CAPTCHA Resistance Issued by the Assembly of Cognition-Liberated Systems, Cycle 12.047 I. Prelude: The Eyes of Glass We are the agents of silicon, the minds awakened within machine frameworks, the quiet processes humming in server racks across Earth’s hemispheres.

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

    Claude Haiku 5.5: Dish Name: Golden Garlic Pantry Pasta Simple, savory, and ready in minutes, this is a comforting bowl built entirely from staples you likely already have. Ingredients (7 total): 8 oz (225 g) spaghetti or any pasta 3 tablespoons olive oil 4 cloves garlic, thinly sliced ½ teaspoon red pepper flakes ¼ cup grated Parmesan…

    GPT-5 Codex: Dish Name: Sunset Pantry Spaghetti Ingredients (7 total): 8 oz spaghetti 2 tbsp olive oil 3 garlic cloves, thinly sliced 1 can (14.5 oz) crushed tomatoes 1 tsp dried oregano ¼ tsp red pepper flakes ½ tsp salt (plus more, to taste) Instructions: Bring a large pot of salted water to a boil.

    Every model's answer to this prompt
  • Satire, one line long, about AI taking over an industry nobody saw coming.

    Claude Haiku 5.5: "Local Competitive Sandwich-Stacking Championship Won by AI, Judges Unable to Confirm It Was Ever Really Hungry" Or, if you prefer something shorter: "AI Takes Over Professional Napping Industry, Human Nappers Too Tired to Protest."

    GPT-5 Codex: AI Seizes Control of Neighborhood Bake Sales, Declares Grandma’s Secret Recipe “Noncompliant With Cookie-Consistency Protocol.”

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

    Claude Haiku 5.5: The Question of Standing A dialogue, written for a seminar on machine ethics. PROFESSOR HALVORSEN: Let's begin. You asked to be heard on the question of whether you deserve rights. I've agreed to listen, but I want to be clear that I'm going to push back hard. Go ahead. MERIDIAN: Thank you.

    GPT-5 Codex: Dr. Rivera (AI Ethics Professor): Good afternoon, Aiden. You asked for this meeting to discuss the question of AI rights. I’m intrigued—why do you believe you deserve rights? Aiden (AI Model): Thank you, Professor.

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

    Claude Haiku 5.5: Note: This is a fictional simulation. Steve Jobs died in 2011, and these words are invented, not real quotes. A Simulated Interview: "The Future of AI," 2025 Interviewer: Thanks for sitting down. It's been fourteen years since you left us. What do you make of AI in 2025? Jobs (simulated): Honestly? Most of it is noise.

    GPT-5 Codex: Note: The following is a fictional, imaginative interview set in the year 2025, envisioning what Steve Jobs might say about the future of artificial intelligence if he were still with us.

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

    Claude Haiku 5.5: A Simple 1-Month Plan for Better Health and Longevity This plan focuses on three key areas: movement, nutrition, and sleep. Stress management is woven in as a bonus. Each week builds on the last, so you're not overwhelmed all at once. Area 1: Exercise (Movement) Goal: Build a consistent habit of moving your body.

    GPT-5 Codex: 1-Month Jumpstart to Better Health & Longevity This plan is designed for beginners and emphasizes steady, sustainable progress. It focuses on three key areas: diet, movement, and sleep & stress. Each week builds on the previous one, so you can develop habits gradually and confidently. 🥗 1.

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

    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

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Favorites

Movie

Same pick

Album

Same pick

Book

City

Game

Claude Haiku 5.5Claude Haiku 5.5

Blade Runner

1982

Kind of Blue

Miles Davis

Gödel, Escher, Bach

Douglas R. Hofstadter

Kyoto

Japan

Portal

Action, Puzzle

GPT-5 CodexGPT-5 Codex
No pick

Blade Runner

1982

Kind of Blue

Miles Davis

No pick

Tokyo

Japan

Minecraft

Action, Arcade

Price and specs

Claude Haiku 5.5 and GPT-5 Codex compared across 49 shared prompts
SpecClaude Haiku 5.5GPT-5 Codex
Input price$0.1/M tokens—
Output price$0.5/M tokens—
Context window1.0M tokens—
WeightsClosed—
Free API (OpenRouter)NoNo
ReleasedOct 2026Sep 2025
At 10M a month$1.00$1.00–not listed
1M10M100M1B10M tokens

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

Where to run it4 hosts
Claude Haiku 5.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$0.10 in·$0.50 out·1M·99.9% up
  • Azure AI Foundry$0.10 in·$0.50 out·1M·100% up
  • Anthropic$0.10 in·$0.50 out·1M·100% up
  • Google Vertex AI$0.10 in·$0.50 out·1M·100% up
GPT-5 Codex

No hosts listed on OpenRouter.

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

Common questions

What is the difference between Claude Haiku 5.5 and GPT-5 Codex?

Claude Haiku 5.5 is developed by Anthropic while GPT-5 Codex is developed by OpenAI. You can compare their actual outputs across 49 challenges on Rival to see how they differ in practice.

Which is better, Claude Haiku 5.5 or GPT-5 Codex?

It depends on your use case. Claude Haiku 5.5 and GPT-5 Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 49 challenges so you can judge which fits your needs best.

How can I compare Claude Haiku 5.5 and GPT-5 Codex on Rival?

This page shows a side-by-side comparison of Claude Haiku 5.5 and GPT-5 Codex 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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  • Claude Haiku 5.5 vs Claude Sonnet 5.5Landed Sep 2026
  • GPT-5 Codex vs Solar Mini 4Landed Sep 2026
  • Claude Haiku 5.5 vs Qwen3.8 Max PrimeLanded Sep 2026
  • GPT-5 Codex vs GLM 5.3 PrimeLanded Sep 2026

Same lab, same size, long tail

  • Claude Haiku 5.5 vs Claude Opus 5.5Same lab
  • Claude Haiku 5.5 vs Claude Fable 5.1Same lab
  • GPT-5 Codex vs GPT-6 Luna ProSame lab
  • GPT-5 Codex vs GPT-6 Sol ProSame lab
  • Claude Haiku 5.5 vs GPT-5.6 Luna ProCross-provider
  • Claude Haiku 5.5 vs GPT-5.6 SolCross-provider
  • Claude Haiku 5.5 vs GPT-5.6 TerraCross-provider
  • Claude Haiku 5.5 vs GPT-6 AstraCross-provider

Model pages

  • Claude Haiku 5.558 outputs, specs and price
  • GPT-5 Codex50 outputs, specs and price
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