Skip to content
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare models
  • All models
  • Image comparison
  • Audio comparison
  • Image generation
  • Best AI for...
  • Arena
  • API pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model updates
  • Provider status
  • AI creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy policy
  • Terms
  • RSS feed
  1. Home/
  2. Compare/
  3. Claude 3 Opus vs Claude Sonnet 4.5
Updated Sep 2025

Claude 3 Opus vs Claude Sonnet 4.5

Claude Sonnet 4.5 is cheaper than Claude 3 Opus at $3/M vs $15/M input tokens.

Pokémon Battle UI Recreation

Pokémon battle screen you can actually click. One HTML file.

Loading the build
Claude 3 Opus
Loading the build
Claude Sonnet 4.5

Which answer wins?

Written rounds

3 prompts
  • 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.

    Every model's answer to this prompt
  • 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.

    Every model's answer to this prompt
  • 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?

    Every model's answer to this prompt

Price and specs

Claude 3 Opus and Claude Sonnet 4.5 compared across 12 shared prompts
SpecClaude 3 OpusClaude Sonnet 4.5
Input price$15/M tokens$3/M tokens
Output price$75/M tokens$15/M tokens
Context window200K tokens200K tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedMar 2024Sep 2025
At 10M a month$150$150$30.00$30.00
1M10M100M1B10M tokens

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

Where to run it4 hosts
Claude 3 Opus

No hosts listed on OpenRouter.

Claude Sonnet 4.54 hosts
HostInOutContextUptime
  • Amazon Bedrock$3.00 in·$15.00 out·1M·100% up
  • Azure AI Foundry$3.00 in·$15.00 out·200k·100% up
  • Anthropic$3.00 in·$15.00 out·1M·100% up
  • Google Vertex AI$3.00 in·$15.00 out·1M·99.9% up

Per million tokens. Prices and uptime via OpenRouter, checked 5 Oct 2026.

Common questions

What is the difference between Claude 3 Opus and Claude Sonnet 4.5?

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.

Which is better, Claude 3 Opus or Claude Sonnet 4.5?

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.

How much does Claude 3 Opus cost compared to Claude Sonnet 4.5?

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.

How can I compare Claude 3 Opus and Claude Sonnet 4.5 on Rival?

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.

More comparisons

Against the newest arrivals

  • Claude 3 Opus vs GPT-6.1 SolLanded Sep 2026
  • Claude Sonnet 4.5 vs Claude Sonnet 5.5Landed Sep 2026
  • Claude 3 Opus vs Solar Mini 4Landed Sep 2026
  • Claude Sonnet 4.5 vs Qwen3.8 Max PrimeLanded Sep 2026
  • Claude 3 Opus vs GLM 5.3 PrimeLanded Sep 2026
  • Claude Sonnet 4.5 vs Qwen3.8 Omni FlashLanded Sep 2026
  • Claude 3 Opus vs Command A+Landed Sep 2026
  • Claude Sonnet 4.5 vs Claude Opus 5.5Landed Sep 2026

Same lab, same size, long tail

  • Claude 3 Opus vs Claude Opus 4.6Version compare
  • Claude 3 Opus vs Claude Sonnet 5.5Version compare
  • Claude Sonnet 4.5 vs Claude Opus 4.6Same lab
  • Claude Sonnet 4.5 vs Claude Fable 5.1Same lab
  • Claude Sonnet 4.5 vs GLM 4.6New provider
  • Claude 3 Opus vs GLM 5Same size
  • Claude 3 Opus vs GLM 5 TurboNew provider
  • Claude 3 Opus vs GLM 5.1New provider

Model pages

  • Claude 3 Opus12 outputs, specs and price
  • Claude Sonnet 4.543 outputs, specs and price
Workshop · 150 skills

Build your own version.

Editable skills and working examples for your agent.

Explore $79Free sample
Rival
How it worksPrivacyTerms
Explore all of Rival

Explore

  • Compare models
  • All models
  • Image comparison
  • Audio comparison
  • Image generation
  • Best AI for...
  • Arena
  • API pricing
  • Challenges

Discover

  • SubjectiveBench
  • Default Index
  • Research
  • Research downloads
  • Rival Kits
  • Find your AI taste
  • UI Glow-Up
  • VoiceLock
  • Cost Cutter
  • Agent skills
  • Benchmarks vs Vibes
  • Brief
  • Jailbreak
  • Model updates
  • Provider status
  • AI creators

Connect

  • Methodology
  • Advertise
  • Partnerships
  • Privacy policy
  • Terms
  • RSS feed