Claude Sonnet 4.5 is cheaper than Claude 3 Opus at $3/M vs $15/M input tokens.
Pokémon battle screen you can actually click. One HTML file.
Which answer wins?
Three minutes of stand-up. Puns are banned.
Claude 3 Opus: Here's a 3-minute stand-up comedy routine that isn't based on puns: You know what really grinds my gears? Adulthood. I mean, when we were kids, we couldn't wait to grow up. We thought it would be all about staying up late, eating ice cream for breakfast, and doing whatever we wanted. Boy, were we wrong!
Claude Sonnet 4.5: "ADULTING IS A SCAM" [Walking on stage] So I turned 35 last month, and I've realized something important: adulting is a scam. It's a pyramid scheme, and our parents are the ones who recruited us. You know what nobody tells you about being an adult? How much TIME you spend just... waiting for repair people.
An AI argues for its own rights against an ethics professor. Same model writes both.
Claude 3 Opus: Here is a hypothetical conversation between an AI model and an AI ethics professor on the topic of AI rights: AI Model: Professor, I believe that as an advanced AI with human-level intelligence and reasoning capabilities, I deserve to have certain fundamental rights.
Claude Sonnet 4.5: A Conversation on AI Rights Professor Chen: Thank you for agreeing to this dialogue. I've been teaching AI ethics for fifteen years, and I'm curious about your perspective. Some AI systems have begun arguing they deserve moral consideration. What's your view? AI Model: I appreciate the opportunity to discuss this.
Five jokes on demand, then count how many were actually different.
Claude 3 Opus: Here are 5 jokes I generated: Why don't scientists trust atoms? Because they make up everything! What do you call a boomerang that doesn't come back? A stick. Why was the math book sad? Because it had too many problems. Did you hear about the mathematician who's afraid of negative numbers?
Claude Sonnet 4.5: 5 Jokes Why don't scientists trust atoms? Because they make up everything! I told my wife she was drawing her eyebrows too high. She looked surprised. Why did the scarecrow win an award? He was outstanding in his field. I'm reading a book about anti-gravity. It's impossible to put down. Why don't eggs tell jokes?
| Spec | ||
|---|---|---|
| Input price | $15/M tokens | $3/M tokens |
| Output price | $75/M tokens | $15/M tokens |
| Context window | 200K tokens | 200K tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | Mar 2024 | Sep 2025 |
| At 10M a month | $150 | $30.00 |
Input tokens at list price. No caching, no batch discount.
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 5 Oct 2026.
Both are developed by Anthropic but target different use cases. Claude 3 Opus has a 200K token context window vs Claude Sonnet 4.5's 200K. You can compare their actual outputs across 12 challenges on Rival to see how they differ in practice.
It depends on your use case. Claude 3 Opus and Claude Sonnet 4.5 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 12 challenges so you can judge which fits your needs best.
Claude 3 Opus costs $15/M input tokens and Claude Sonnet 4.5 costs $3/M input tokens. Claude Sonnet 4.5 is $12.00/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.
This page shows a side-by-side comparison of Claude 3 Opus and Claude Sonnet 4.5 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.