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

Claude Opus 5 (Fast) and Phi 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.

Phi 4, from Microsoft, has a 16,384-token context window and is priced at $0.07/M tokens input, $0.14/M tokens output on OpenRouter.

Context window

• Claude Opus 5 (Fast): 1,000,000 tokens
• Phi 4: 16,384 tokens

Price

• Claude Opus 5 (Fast): $10/M tokens input, $50/M tokens output
• Phi 4: $0.07/M tokens input, $0.14/M tokens output

Provided by

• Claude Opus 5 (Fast): Anthropic
• Phi 4: Microsoft

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