GLM-5.2 vs Claude Opus
techstackups.com ● Covered by 3 sources
GLM-5.2, an open-weights model from Z.ai, was benchmarked against Claude Opus 4.8 in a head-to-head test building a 3D platformer game in raw WebGL from scratch. GLM-5.2 took 1 hour 10 minutes and cost $5.39, while Opus finished in 33 minutes and cost approximately $21.92. Opus shipped a cleaner, more correct game with proper textures and working mechanics, while GLM-5.2's game had missing textures, a backwards-facing character, and non-functional hazards—partly because GLM-5.2 cannot read images and thus failed to catch visual problems during verification, whereas Opus's multimodal capabilities let it inspect screenshots and fix issues before shipping.
Why it matters
Tech Stackups tested open-weights GLM-5.2 against Claude Opus 4.8 on a one-shot "build a 3D WebGL platformer from scratch" task: Opus was faster and shipped a cleaner, more correct game, while GLM-5.2 was much cheaper but rougher and, being text-only, couldn't visually self-check its work.
