Z.ai's GLM-5.3 Language Model Available Via API at Competitive Price

Chinese startup z.ai has made its new GLM-5.3 open-source language model available through its application programming interface (API). This allows developers to integrate the model into their applications and agents.

The GLM-5.3 API release provides developers access to a model that reportedly offers significantly improved coding capabilities and longer-horizon agent functions compared to its predecessor, GLM-5.2. API pricing remains unchanged: $1.40 per million input tokens and $4.40 per million output tokens. The company also plans to make the model weights openly available, though specific dates and licensing terms are pending.

While token prices are consistent, the model's performance improvements are notable. According to recent independent benchmarks, GLM-5.3 scored 60 on Artificial Analysis's Intelligence Index, matching Kimi K3 and surpassing GLM-5.2 by seven points. The model's pricing positions it competitively against several other API offerings.

GLM-5.3 is not the cheapest model on the market, with options like Google's Gemini 3.7 Flash and OpenAI's GPT-5.6 Luna priced lower. However, z.ai's pricing places GLM-5.3 in a more cost-effective tier compared to many other leading-edge models. For developers, this presents a new, economical option for building advanced coding and agent solutions.