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

Claude Opus 5 (Fast) and Inkling Small 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.

Inkling Small, from thinkingmachines, has a 1,048,576-token context window and is priced at $0.45/M tokens input, $1.20/M tokens output on OpenRouter.

Context window

• Claude Opus 5 (Fast): 1,000,000 tokens
• Inkling Small: 1,048,576 tokens

Price

• Claude Opus 5 (Fast): $10/M tokens input, $50/M tokens output
• Inkling Small: $0.45/M tokens input, $1.20/M tokens output

Provided by

• Claude Opus 5 (Fast): Anthropic
• Inkling Small: thinkingmachines

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