What they did
HN user tkgally tests new models by asking them for self-contained web pages that show clocks, a personal benchmark in the spirit of Simon Willison's pelican drawings. Impressed by Claude Opus 5.5, they kept going across several sessions in the Claude chat interface and had it build 500 clocks with minimal direction. Nearly every idea came from the model, and every graphic is drawn in JavaScript with no image files. Claude also wrote the repository README explaining how the page was prompted and structured, on the instruction to keep it plain and to say that all the code and writing were Claude's.
How it went
The result is one 6.3 MB HTML file with 500 clocks, including a Pong clock, an interactive fiction clock and clocks wrapped around board games such as Mancala and Scrabble. Claude estimated about 15 million tokens in total, with sessions of 490,000 to 670,000 tokens each, which used a large share of the author's weekly Max plan. The author says themes repeat and some clocks are rough, and they would refine one further before using it on its own.
Worth knowing
Commenters were split: some praised the variety, others called most designs cheap-looking or said some, like a Lorenz attractor, had little to do with telling time. The author suggests seeding the model with original ideas to keep variety at larger counts.