GLM-5.2 vs Claude Opus 4.8: a real coding test

GLM 5.2 vs. Opus

Tech Stackups had both models build a raw WebGL 3D platformer from scratch, no game engine. Opus 4.8 finished in 33 minutes with a cleaner result and can check its own visual output. GLM-5.2 took 1h 10m but cost only $5.39, about a quarter of Opus. GLM-5.2 is text-only and can't read images, a real limitation for screenshot-based workflows. The verdict: Opus stays the daily driver, but GLM-5.2 earns a permanent spot for being cheap, open-weight, and always available.

Why it matters: First-person experiment with concrete time and cost data, not a benchmark rehash. Opus shipped in 33 min vs GLM-5.2's 1h10m at a quarter of the cost—enough signal for featured. Not scored higher because the coding-only scenario is narrow, and the article body is truncated, mis...