Z.ai

Zhipu AI's free chat interface powered by the GLM family of large language models.

Freemium· Free chat tier; paid API and Pro plans via z.ai open platformWritingGLM-5.2 (GLM family)

Best for

Pick Z.ai if you want a free, capable ChatGPT alternative backed by a lab that also ships open-weights versions of its models.

Skip if

Skip it if your organization has data-residency or vendor restrictions that exclude China-based AI providers.

Z.ai is the consumer-facing chat product from Zhipu AI, one of China's most prominent foundation-model labs. It exposes the GLM model family (currently GLM-5.2, with prior generations including GLM-4.5 and GLM-4.6) through a familiar ChatGPT-style interface, with support for general Q&A, long-form writing, code generation, agentic browsing, and document analysis. The site at chat.z.ai is the English-language front door; developers can also hit the same models via the Z.ai open platform API.

What sets Z.ai apart is the underlying GLM lineage: Zhipu has consistently released open-weights variants of its flagship models (GLM-4, GLM-4.5-Air, CodeGeeX, etc.) on Hugging Face, making it one of the few labs offering both a hosted chat product and downloadable weights of competitive frontier-class models. The chat product itself is free to use with no hard credit system, which makes it a viable daily-driver alternative to ChatGPT or Claude.ai for users who want a capable assistant without a subscription. Paid tiers and API pricing exist for higher throughput and the largest models.

Integrations include a built-in agent mode (web search, file upload, deep research), image generation via Zhipu's CogView models, and a coding-focused assistant. Caveats: the service is operated from China with the English property carved out specifically for international users, so data-residency and policy expectations should be checked against your own compliance bar before using it for sensitive work.

Editor's take

Z.ai is the most polished way to try the GLM family without spinning up your own inference. The free tier is generous, the agent mode actually works, and the open-weights backstop means you're not fully locked in. Just be deliberate about what you paste into it.

— The AI Tool Bible editorial team