Claude Opus 5 (Fast) vs Mistral Small 4: side-by-side summary

Claude Opus 5 (Fast) and Mistral Small 4 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.

Mistral Small 4, from Mistral AI, has a 262,144-token context window and is priced at $0.15/M tokens input, $0.60/M tokens output on OpenRouter.

Context window

• Claude Opus 5 (Fast): 1,000,000 tokens
• Mistral Small 4: 262,144 tokens

Price

• Claude Opus 5 (Fast): $10/M tokens input, $50/M tokens output
• Mistral Small 4: $0.15/M tokens input, $0.60/M tokens output

Provided by

• Claude Opus 5 (Fast): Anthropic
• Mistral Small 4: Mistral AI

• Claude Opus 5 (Fast) model details, providers and pricing
• Mistral Small 4 model details, providers and pricing