Claude Opus 5.5 animates entire scenes from JS or Python code

Anthropic shipped Claude Opus 5.5 on September 22, and the model’s ability to draw its own animations directly through code turned into the fastest-spreading part of the release. Ask it to build a scene, specify Python or JavaScript, and it writes every frame itself rather than pulling in stock assets or a rendering library to do the visual work for it.

One example captured just how far that goes. Developer Chris Riley asked for a square animated film as a single HTML file using WebGL2 and plain JavaScript — no libraries, no image files, no fonts, no audio. What came back ran 80 seconds: glass tiles lift off a wall and reassemble into moving figures, fish, cranes, doves, through flocking behavior the model coded from scratch, then the scene shifts from day to night with constellations appearing overhead before the tiles disperse in a spiral to close it out. Nothing in that sequence came from a premade asset. The model generated the geometry, the motion, and the lighting logic as code, live.

The animation trick isn’t really separate from what Anthropic is claiming about the model underneath it. Output pricing dropped to $20 per million tokens from $25, and Anthropic says Opus 5.5 beats the larger Fable model on a range of benchmarks while running faster, a smaller model outperforming a bigger one being the part of the pitch the company leans on hardest. It also puts Opus 5.5’s capability level in biology and cybersecurity on par with Mythos, a comparison Anthropic makes deliberately rather than in passing.

The release lands right after CEO Dario Amodei publicly backed calls to slow frontier AI progress deliberately, arguing that fully addressing the risks “requires even more prudence” and that capability gains should stay paced with how fast risk prevention can actually keep up. Opus 5.5 is the first model out the door since he said that, and Anthropic is calling it the strongest-performing model the company has tested to date. Sonnet 5.5 and Haiku 5.5 are due in the coming weeks with similar improvements, following the same pattern of lower prices paired with a step up in what the model can actually do. It’s the same instinct behind an earlier Opus 5 demo built entirely from code, just with a faster, cheaper model doing noticeably more with it this time.