Comprehensive side-by-side LLM comparison
Both models show comparable benchmark performance. Both models have their strengths depending on your specific coding needs.
Zhipu AI
GLM-5 is a large language model from Zhipu AI with 745 billion total parameters and 44 billion active parameters per inference, designed for agentic intelligence, advanced reasoning, and frontier-level performance. It features a 200K token context window and targets complex multi-step tasks requiring sustained reasoning and tool use. GLM-5 is available via Zhipu AI's Z.ai platform under an MIT license.
OpenAI
GPT-5 Codex, released by OpenAI in August 2025, is a coding-specialized large language model from the GPT-5 family engineered for software engineering, code generation, and agentic development workflows. It builds on GPT-5's architecture with optimizations targeting multi-file code editing, test generation, and automated debugging. GPT-5 Codex targets developers and agentic coding tools requiring a model tuned specifically for programming tasks.
6 months newer

GPT-5 Codex
OpenAI
2025-08
GLM 5
Zhipu AI
2026-02-11
Context window and performance specifications
Average performance across 2 common benchmarks
GLM 5
GPT-5 Codex
Performance comparison across key benchmark categories
GLM 5
GPT-5 Codex
Available providers and their performance metrics
GLM 5
Zhipu AI
GPT-5 Codex
GLM 5
GPT-5 Codex
GLM 5
GPT-5 Codex