Z.ai: GLM 5.1 vs GPT-5
Compare Z.ai: GLM 5.1 by Z-ai against GPT-5 by OpenAI, context windows of 203K vs 400K, tested across 50 shared challenges. Updated May 2026.
Which is better, Z.ai: GLM 5.1 or GPT-5?
Z.ai: GLM 5.1 and GPT-5 are both competitive models. Z.ai: GLM 5.1 costs $1.4/M input tokens vs $1.25/M for GPT-5. Context windows: 203K vs 400K tokens. Compare their real outputs side by side below.
Key Differences Between Z.ai: GLM 5.1 and GPT-5
Z.ai: GLM 5.1 is made by z-ai while GPT-5 is from openai. Z.ai: GLM 5.1 has a 203K token context window compared to GPT-5's 400K. On pricing, Z.ai: GLM 5.1 costs $1.4/M input tokens vs $1.25/M for GPT-5.
Per 1M tokens
GPT-5 wins input (1.1× cheaper)·Z.ai: GLM 5.1 wins output (2.3× cheaper)
No community votes yet. On paper, GPT-5 has the edge — bigger model tier, bigger context window, major provider backing.
Style Comparison
Z.ai: GLM 5.1 uses 19.3x more bold
