Testing GLM-4.5 via Claude Code: A Practical Review of Coding Performance and Alternatives

Why Look Beyond Anthropic Models on Claude Code?

Recent discussions on social media and Anthropic's own communications acknowledge performance degradation in both Claude Opus and Sonnet models. While Anthropic has addressed these issues, the lack of transparency around the specific problems has left some users exploring alternative models within the Claude Code environment.

GLM-4.5: Coding Performance and Pricing

GLM-4.5 demonstrates strong performance on coding benchmarks, particularly on the SWE (Software Engineering) benchmark and agentic coding tasks. The model offers two specialized coding plans:

Implementation and Setup

GLM models can be accessed through Claude Code by modifying the configuration to use alternative API endpoints. For users concerned about using Chinese-based models, the same approach works with American providers via OpenRouter:

Practical Testing: Three Coding Projects

Space Invaders Game Implementation

The prompt requested a "fancy, modern Space Invaders game with animations and rich graphics using only Pygame." GLM-4.5 successfully created a complete, playable game with neon visuals and proper collision detection in a single execution.

Hexagon Ball Simulation

The model built an interactive simulation featuring a hexagon containing five bouncing balls with wall collision physics, plus functional sliders for speed control and buttons to add more balls. The implementation worked correctly on first execution.

Solar System HTML Simulation

For web development testing, GLM-4.5 created an interactive solar system simulation with zoom controls, speed adjustment, and informational popups. The HTML implementation included modern styling and smooth animations as requested.

Other Viable Open-Source Alternatives

Beyond GLM-4.5, several other models show strong coding capabilities within Claude Code:

• DeepSeek Coder: Strong performance on coding tasks with good reasoning capabilities
• Qwen models: Competitive coding performance though with potentially longer thinking time
• CodeLlama variants: Specialized coding models with strong community support

Considerations for Model Selection

When choosing alternative models for Claude Code, consider these factors:

Conclusion

GLM-4.5 demonstrates impressive coding capabilities within Claude Code, particularly for game development and interactive simulations. The model's speed and accuracy in completing complex coding tasks make it a viable alternative to Anthropic's models, especially considering the current performance issues some users are experiencing.

For users seeking open-source alternatives, both GLM-4.5 and DeepSeek models provide strong coding performance. The availability of these models through American providers via OpenRouter addresses geographical concerns while maintaining access to competitive AI coding assistance.