Doubao-Seedream-4.5 vs gpt-5-nano

ByteDance Doubao-Seedream-4.5OpenAI gpt-5-nano
VendorByteDanceOpenAI
Context window—400,000
Max output—128,000
ReasoningNoYes
Tool callingNoYes
File inputYesYes
Inputtext, imagetext, image
Outputimagetext
Released2025-09-262025-08-07