Claude Sonnet 5.5 vs o4-mini

Anthropic Claude Claude Sonnet 5.5OpenAI o4-mini
VendorAnthropic ClaudeOpenAI
Context window1,000,000200,000
Max output128,000100,000
ReasoningYesYes
Tool callingYesYes
File inputYesYes
Inputtext, image, filetext, image
Outputtexttext
Released2026-09-282025-04-16