GLM-5.2 vs Claude Opus 4.8: Open Model Rivals in 3D Game Test
Original: GLM 5.2 vs. Opus
Why This Matters
Open-weights models challenging closed-model dominance on practical coding tasks while offering significant cost reduction.
Tech Stackups tested GLM-5.2 against Claude Opus 4.8 by tasking both to build a 3D platformer in raw WebGL. Opus was faster (33m 30s vs 1h 10m 40s) and produced cleaner output, but GLM-5.2 cost one-fifth the price ($5.39 vs ~$21.92) as an open-weights model.
GLM-5.2, Z.ai's latest flagship model released under MIT license, was benchmarked against Claude Opus 4.8 in a practical coding task. The challenge: build a 3D platformer game from scratch using raw WebGL without game engines or 3D libraries. Results showed Opus completed the task in 33 minutes 30 seconds compared to GLM-5.2's 1 hour 10 minutes 40 seconds. Opus consumed 216,809 output tokens while GLM-5.2 used 131,000. Pricing per 1M tokens heavily favored GLM-5.2: $1.4 input, $0.26 cache read, $4.4 output versus Opus's $5, $0.50, $25. Both games are playable online with source code publicly available. GLM-5.2 features a 1M-token context window and two thinking effort levels (High and Max), though it is text-only without image capabilities. The model can be run via API or locally using frameworks like vLLM. The tester concluded Opus remains the primary choice for production due to speed and visual verification capabilities, but GLM-5.2 earned permanent inclusion as a cost-effective alternative with guaranteed availability through open weights.