GPT-5.6 Terra Pro vs Sonar Reasoning Pro: side-by-side summary

GPT-5.6 Terra Pro and Sonar Reasoning Pro 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 $2/M tokens input, $12/M tokens output on OpenRouter.

Sonar Reasoning Pro, from Perplexity, has a 128,000-token context window and is priced at $2/M tokens input, $8/M tokens output on OpenRouter.

Context window

• GPT-5.6 Terra Pro: 1,050,000 tokens
• Sonar Reasoning Pro: 128,000 tokens

Price

• GPT-5.6 Terra Pro: $2/M tokens input, $12/M tokens output
• Sonar Reasoning Pro: $2/M tokens input, $8/M tokens output

Provided by

• GPT-5.6 Terra Pro: OpenAI
• Sonar Reasoning Pro: Perplexity

• GPT-5.6 Terra Pro model details, providers and pricing
• Sonar Reasoning Pro model details, providers and pricing