Doubao-Seedream-5.0-pro vs GPT-5.1

ByteDance Doubao-Seedream-5.0-proOpenAI GPT-5.1
VendorByteDanceOpenAI
Context window—400,000
Max output—128,000
ReasoningNoYes
Tool callingNoYes
File inputYesYes
Inputtext, imagetext, image
Outputimagetext
Released2026-07-082025-11-12