GLM 5.3 Flash vs o4-mini

Z.ai GLM 5.3 FlashOpenAI o4-mini
VendorZ.aiOpenAI
Context window1,000,000200,000
Max output128,000100,000
ReasoningYesYes
Tool callingYesYes
File inputNoYes
Inputtexttext, image
Outputtexttext
Released2026-08-262025-04-16