Compare Claude Opus 4 by Anthropic against Aurora Alpha by OpenRouter, context windows of 200K vs 128K, tested across 35 shared challenges. Updated February 2026.
35 challenges
Tests an AI's ability to solve a simple but potentially confusing logic puzzle
I need to work through this step-by-step.
Given information:
Since Sally is one of the sisters that each brother has, and each brother has 2 sisters total, that means th ere must be exactly 2 sisters in the family.
The 2 sisters are:
Therefore, Sally has 1 sister.
Sally has one sister.
Reasoning
Thus the total number of sisters in the family is 2. One of those sisters is Sally, leaving one other sister for her. So Sally has one sister.
Tests an AI's randomness and creativity
Here are 5 jokes:
Why don't scientists trust atoms? Because they make up everything!
What do you call a bear with no teeth? A gummy bear!
Why did the scarecrow win an award? He was outstanding in his field!
What do you call a fake noodle? An impasta!
Why don't eggs tell jokes? They'd crack up!
All 5 jokes are unique - each one has a different setup and punchline, covering different topics (atoms/scie nce, bears, scarecrows, pasta, and eggs).
Here are five jokes for you:
Why did the scarecrow win an award?
Because he was outstanding in his field!
What do you call fake spaghetti?
An impasta.
Why don’t scientists trust atoms?
Because they make up everything.
How does a penguin build its house?
Igloos it together.
What’s orange and sounds like a parrot?
A carrot.
How many are unique?
All five jokes are distinct, so there are 5 unique jokes.
Tests an AI's ability to generate vector graphics
Tests an AI's ability to create detailed SVG illustrations of gaming hardware
Tests an AI's humor and creative writing ability
Recreate an interactive, nostalgic Pokémon battle UI in a single HTML file.
Create a 3D building and driving game in a single self-contained HTML file using Three.js. Tests an AI's ability to combine 3D graphics, game logic, and UI interactions on the web.
Recreate an interactive, classic Mario level in a single HTML file.
Tests an AI's ability to replicate an existing UI with Tailwind CSS
Tests an AI's ability to create interactive web elements
Tests an AI's ability to create a detailed world map in SVG format
Generate a single-page, self-contained HTML webapp using Tailwind CSS for a randomly chosen category/industry/niche.
