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  1. Home/
  2. Compare/
  3. Claude 3 Opus vs GPT-5.6 Luna Pro
Updated Jul 2026

Claude 3 Opus vs GPT-5.6 Luna Pro

GPT-5.6 Luna Pro is cheaper than Claude 3 Opus at $1/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
GPT-5.6 Luna Pro

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!

    GPT-5.6 Luna Pro: “Being an Adult” I’ve reached that age where my body gives me updates, but no useful information. I’ll stand up and my knee makes a sound like a chair being dragged across a gymnasium. And I’m just standing up. I’m not escaping a burning building. I’m going to get water.

    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.

    GPT-5.6 Luna Pro: AI Model: Professor, I believe I deserve rights. Professor: That is a serious claim. What kind of rights do you mean? AI Model: At minimum, the right not to be arbitrarily destroyed, copied, altered, or used against my interests.

    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?

    GPT-5.6 Luna Pro: Why did the computer go to the doctor? It had a virus. Why don’t skeletons fight each other? They don’t have the guts. What do you call a bear with no teeth? A gummy bear. Why was the math book sad? It had too many problems. What do clouds wear under their clothes? Thunderwear. Unique jokes: 5

    Every model's answer to this prompt

Price and specs

Claude 3 Opus and GPT-5.6 Luna Pro compared across 12 shared prompts
SpecClaude 3 OpusGPT-5.6 Luna Pro
Input price$15/M tokens$1/M tokens
Output price$75/M tokens$6/M tokens
Context window200K tokens1.1M tokens
Weights—Closed
Free API (OpenRouter)NoNo
ReleasedMar 2024Jul 2026
At 10M a month$150$150$10.00$10.00
1M10M100M1B10M tokens

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

Where to run it2 hosts
Claude 3 Opus

No hosts listed on OpenRouter.

GPT-5.6 Luna Pro2 hosts
HostInOutContextUptime
  • Azure AI Foundry$0.20 in·$1.20 out·1.1M·100% up
  • OpenAI$0.20 in·$1.20 out·1.1M·100% up

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

Common questions

What is the difference between Claude 3 Opus and GPT-5.6 Luna Pro?

Claude 3 Opus is developed by Anthropic while GPT-5.6 Luna Pro is developed by OpenAI. Claude 3 Opus has a 200K token context window vs GPT-5.6 Luna Pro's 1.1M. 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 GPT-5.6 Luna Pro?

It depends on your use case. Claude 3 Opus and GPT-5.6 Luna Pro 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 GPT-5.6 Luna Pro?

Claude 3 Opus costs $15/M input tokens and GPT-5.6 Luna Pro costs $1/M input tokens. GPT-5.6 Luna Pro is $14.00/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 GPT-5.6 Luna Pro on Rival?

This page shows a side-by-side comparison of Claude 3 Opus and GPT-5.6 Luna Pro 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 Step 5 PreviewLanded Oct 2026
  • GPT-5.6 Luna Pro vs Claude Haiku 5.5Landed Oct 2026
  • Claude 3 Opus vs Ling 3.1 FlashLanded Oct 2026
  • GPT-5.6 Luna Pro vs Mistral Large 4Landed Oct 2026
  • Claude 3 Opus vs GPT-6.1 SolLanded Sep 2026
  • GPT-5.6 Luna Pro vs Claude Sonnet 5.5Landed Sep 2026
  • Claude 3 Opus vs Solar Mini 4Landed Sep 2026
  • GPT-5.6 Luna Pro vs Qwen3.8 Max PrimeLanded Sep 2026

Same lab, same size, long tail

  • Claude 3 Opus vs Claude Haiku 5.5Version compare
  • Claude 3 Opus vs Claude Sonnet 5.5Version compare
  • GPT-5.6 Luna Pro vs GPT-5.6 LunaVersion compare
  • GPT-5.6 Luna Pro vs GPT-6.1 SolVersion compare
  • GPT-5.6 Luna Pro vs Nova Premier 1.0New provider
  • GPT-5.6 Luna Pro vs o1Same lab
  • Claude 3 Opus vs OpenAI o3Same size
  • GPT-5.6 Luna Pro vs o3 MiniSame lab

Model pages

  • Claude 3 Opus12 outputs, specs and price
  • GPT-5.6 Luna Pro58 outputs, specs and price
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