GPT-5.6 Terra Pro vs GLM 5.2: side-by-side summary

GPT-5.6 Terra Pro and GLM 5.2 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

GPT-5.6 Terra Pro, from OpenAI, has a 1,050,000-token context window and is priced at $1/M tokens input, $6/M tokens output on OpenRouter.

GLM 5.2, from Z.ai, has a 1,048,576-token context window and is priced at $0.50/M tokens input, $3.15/M tokens output on OpenRouter.

Context window

• GPT-5.6 Terra Pro: 1,050,000 tokens
• GLM 5.2: 1,048,576 tokens

Price

• GPT-5.6 Terra Pro: $1/M tokens input, $6/M tokens output
• GLM 5.2: $0.50/M tokens input, $3.15/M tokens output

Provided by

• GPT-5.6 Terra Pro: OpenAI
• GLM 5.2: Z.ai

• GPT-5.6 Terra Pro model details, providers and pricing
• GLM 5.2 model details, providers and pricing