Doubao-Seed-1.8

What it is

Doubao Large Model 1.8, known as Doubao-Seed-1.8, is a large model from Volcano Engine, the cloud arm of ByteDance. Volcano Engine released it at its FORCE conference on 18 December 2025.^[1] Volcano Engine described it as the latest flagship of ByteDance's Doubao models.^[1]

Origins

The model was launched alongside the Seedance 1.5 pro audio-video model, the AgentKit and HiAgent Workbench agent tools, and an “AI savings plan” that offers tiered discounts of up to 47% on pay-as-you-go model usage.^[1][2] Volcano Engine's president, Tan Dai, said at the launch that daily token usage of the Doubao models had passed 50 trillion, more than ten times the level a year earlier.^[1]

Main features

The model was optimised for multimodal agent scenarios. It has stronger tool calling, better handling of complex instructions and OS-agent abilities, meaning it can operate a computer.^[1]

Its capacity for video understanding has changed in one key way. The number of video frames it can take in a single pass doubled, from 640 to 1,280.^[1]

It can watch very long videos at a low frame rate, and when it needs detail it can call tools to re-examine key segments at a high frame rate. Volcano Engine cited online education and product quality inspection as examples of uses.^[1]

Volcano Engine said the model achieved the best or near-best results on visual reasoning, general visual question answering, spatial understanding and video understanding. It said the model led globally on BrowseComp and came close to top general models in mathematics and reasoning.^[1]

Position in development

Doubao 1.8 is positioned as the latest flagship of the Doubao line. Its focus on agents, tool use and computer operation shows the company placing its large model work on tasks that act on a user's behalf, not only on answering questions.^[1]