t12: Build from a spec -- GPT-6.1 Sol vs Claude Opus 5.5
Build a pricing web page in plain HTML, CSS and JavaScript from a written spec.
Opus: 87.3 s. Sol: 315.1 s. Sol took 3.6 times as long.
Opus (s)Sol (s)
Hidden tests: Opus 15 of 15, Sol 15 of 15.
Blind judge pick: Tie.
"Both solutions perfectly execute the requirements, pass all hidden tests, and demonstrate a strong understanding of vanilla web technologies. They both correctly implement the toggle logic, accessibility features, and responsive design."
"An excellent, well-tested solution that perfectly implements the specification with clean HTML, CSS, and vanilla JavaScript."
"An excellent, pixel-perfect implementation of a responsive pricing page with clean semantic HTML, well-structured CSS, and accessible vanilla JavaScript."