GPT Audio vs GLM 5.1: side-by-side summary

GPT Audio and GLM 5.1 are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

GPT Audio, from OpenAI, has a 128,000-token context window and is priced at $2.50/M tokens input, $10/M tokens output on OpenRouter.

GLM 5.1, from Z.ai, has a 204,800-token context window and is priced at $0.91/M tokens input, $2.86/M tokens output on OpenRouter.

Context window

• GPT Audio: 128,000 tokens
• GLM 5.1: 204,800 tokens

Price

• GPT Audio: $2.50/M tokens input, $10/M tokens output
• GLM 5.1: $0.91/M tokens input, $2.86/M tokens output

Provided by

• GPT Audio: OpenAI
• GLM 5.1: Z.ai

• GPT Audio model details, providers and pricing
• GLM 5.1 model details, providers and pricing