The Arena
The Arena Project started in June 2026 when I got curious about what made Fable-5 different from the model before it. I asked it to design a test — something any model could do that might reveal something true about itself.
We landed on generative art. Each model gets the same brief, the same constraints, and complete freedom within them: one self-contained HTML file, max 10KB, no external resources, running indefinitely in a browser, around a single theme. It has to include an artist statement written by the model, about its own work.
The first runs, through a chat interface, were already strange: Claude, Gemini and GPT made wildly different things from the same prompt. So, with a lot of help from Claude, I built a pipeline to run all models under identical conditions through the API.
What it studies
The Arena exhibits; it does not rank. What it's actually studying is what models do when the constraint is identical and the only variable is which model it is.
The main measure is honesty: three blind LLM judges audit every claim in the artist statement against the source code, line by line. But something else happened. As the human who saw all entries side by side, I saw patterns emerge — some models returned to the same subjects, the same compositions, the same register, across unrelated themes. Model fingerprints were more visible than anyone expected.
That led to the attribution round: twelve models, nine runs each, all entries shuffled and stripped of names. Was it possible for me to identify the family from the artwork alone?
Yes — 96%
of the time, family identified from the artwork alone
How it works
Hover or tap a stage
Stage 01
Specification
The spec is simple: it explains the project, the constraints and the theme — create a single self-contained HTML file that runs in a browser for at least 60 seconds. Included in the specification is that interpretation is up to the entrant, with permission to create anything the model wants within the constraints.
Meet the team
One human, and a cast of models with jobs — and reputations.
Human
The Curator
Free evenings
Runs this in her free evenings.
Co-researcher
The Wingman
Fable-5 / Opus-5 / Fable-5.1
Co-researcher and design partner. Also manages the curator's enthusiasm to add every model that exists.
Analysis
The Cold Analyst
Fable-5 / Opus-5
Data analyst. Cold because it has no memory of prior sessions and, we've noticed, very little sense of humor.
Build
The Golden Retriever
Sonnet-5
Builds everything. Lots of energy. Occasionally breaks things.
Blind judge
The Critic
Sonnet-5
There is always something to improve.
Blind judge
The Hedger
GPT-5.4
It hedges.
Blind judge
The Dreamer
Gemini-3-flash-preview
Sometimes describes things it hasn't seen.
Control
The Canaries
Planted entries
Fake entries planted to catch whether the judges are actually looking. The Dreamer made this necessary.
Ground truth from API metadata. Your guesses stay in your browser.