GLM-5-3 (Flagship) vs Union Alpha (Stealth)

A direct, empirical evaluation of GLM-5-3 (Flagship) (Zhipu AI & THUDM) against Union Alpha (Stealth) (OpenRouter & OpenCode).

GLM-5-3 (Flagship)

Developed by Zhipu AI & THUDM · 744B parameters

Complex algorithmic reasoning, multi-step code synthesis, and long-horizon tool execution.

Union Alpha (Stealth)

Developed by OpenRouter & OpenCode · Multi-Model Ensemble Mixture parameters

Terminal coding agents, pull-request synthesis, multi-model consensus verification, and zero-cost autonomous refactoring.

Metric GLM-5-3 (Flagship) Union Alpha (Stealth)
SWE-bench Verified 54.8% 74.2%
MMLU-Pro 78.4% 89.8%
MATH-500 93.6% 95.4%
Context Window 256,000 tokens 256,000 tokens
Input Pricing (per 1M) $0.55 $0.00
Output Pricing (per 1M) $2.19 $0.00