Claude Opus 5 (Fast) vs Sonar Reasoning Pro: side-by-side summary

Claude Opus 5 (Fast) and Sonar Reasoning Pro are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

Claude Opus 5 (Fast), from Anthropic, has a 1,000,000-token context window and is priced at $10/M tokens input, $50/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

• Claude Opus 5 (Fast): 1,000,000 tokens
• Sonar Reasoning Pro: 128,000 tokens

Price

• Claude Opus 5 (Fast): $10/M tokens input, $50/M tokens output
• Sonar Reasoning Pro: $2/M tokens input, $8/M tokens output

Provided by

• Claude Opus 5 (Fast): Anthropic
• Sonar Reasoning Pro: Perplexity

• Claude Opus 5 (Fast) model details, providers and pricing
• Sonar Reasoning Pro model details, providers and pricing