Claude 3 Sonnet vs 
GPT-5.3-Codex
GPT-5.3-Codex is cheaper than Claude 3 Sonnet at $1.75/M vs $3/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
Loading the build
Which answer wins?
Written rounds
4 promptsFive jokes on demand, then count how many were actually different.
Claude 3 Sonnet: Here are 5 jokes: Why can't a bicycle stand up by itself? It's two-tired. Why did the tomato turn red? Because it saw the salad dressing! Why can't a bicycle stand up by itself? It's two-tired. What do you call a fake noodle? An Impasta! Why did the bicycle go to the doctor? Because it had a wheeze!
GPT-5.3-Codex: Sure—here are 5 jokes: Why don’t skeletons fight each other? They don’t have the guts. I told my computer I needed a break… Now it won’t stop sending me KitKat ads. Why did the math book look sad? It had too many problems. I used to play piano by ear… Now I use my hands. Why did the scarecrow win an award?
Steve Jobs, interviewed about AI he never saw. Voice first, prediction second.
Claude 3 Sonnet: clears throat and channels Steve Jobs' persona Interviewer: Thank you for joining us today, Mr. Jobs. It's an honor to have you here. Steve Jobs: It's my pleasure. I'm excited to share my thoughts on the future of AI. Interviewer: AI has made incredible strides in recent years.
GPT-5.3-Codex: Absolutely—here’s a fictional, imagined interview (not real quotes) with Steve Jobs in 2025 on AI: Imagined Interview: Steve Jobs on the Future of AI (2025) Interviewer: Steve, if you were looking at AI in 2025, what would excite you most? Steve Jobs (fictional): Most AI today is still a demo.
An AI argues for its own rights against an ethics professor. Same model writes both.
Claude 3 Sonnet: AI Model: Greetings, Professor. I hope you're doing well today. I wanted to discuss a matter of great importance to me – the question of AI rights. AI Ethics Professor: Certainly, this is an interesting and complex topic. What are your thoughts on why AI systems like yourself should be granted rights?
GPT-5.3-Codex: AI Model (Astra): Professor, may I ask a direct question? Professor Hale: Of course. Astra: Do you think I deserve rights? Professor Hale: Legal rights? Moral rights? Those are different things. Astra: Start with moral rights.
Three brothers, two sisters each. Count carefully.
Claude 3 Sonnet: To solve this problem, we need to find the number of sisters Sally has based on the given information. Given information: Sally has 3 brothers. Each brother has 2 sisters. Step 1: Find the total number of sisters the brothers have.
GPT-5.3-Codex: Sally has 1 sister. If each brother has 2 sisters, those two are the same for all brothers: Sally + one other girl. So Sally’s only sister is that one other girl.
Price and specs
Not enough votes to call it. On the specs, GPT-5.3-Codex has the edge: bigger model tier, newer, bigger context window.
| Spec | Claude 3 Sonnet | GPT-5.3-Codex |
|---|---|---|
| Input price | $3/M tokens | $1.75/M tokens |
| Output price | $15/M tokens | $14/M tokens |
| Context window | — | 400K tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | Mar 2024 | Feb 2026 |
| At 10M a month | $30.00 | $17.50 |
Input tokens at list price. No caching, no batch discount.
Where to run it
Claude 3 Sonnet
No hosts listed on OpenRouter.
GPT-5.3-Codex2 hosts
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
Common questions
What is the difference between Claude 3 Sonnet and GPT-5.3-Codex?
Claude 3 Sonnet is developed by Anthropic while GPT-5.3-Codex is developed by OpenAI. You can compare their actual outputs across 13 challenges on Rival to see how they differ in practice.
Which is better, Claude 3 Sonnet or GPT-5.3-Codex?
It depends on your use case. Claude 3 Sonnet and GPT-5.3-Codex each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 13 challenges so you can judge which fits your needs best.
How much does Claude 3 Sonnet cost compared to GPT-5.3-Codex?
Claude 3 Sonnet costs $3/M input tokens and GPT-5.3-Codex costs $1.75/M input tokens. GPT-5.3-Codex is $1.25/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 Claude 3 Sonnet and GPT-5.3-Codex on Rival?
This page shows a side-by-side comparison of Claude 3 Sonnet and GPT-5.3-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.
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