Seed 2.1 Pro

Seed 2.1 Pro is ByteDance's flagship model in the Seed line, designed for complex multimodal reasoning, coding, and agents. It has a 256,000-token context window and a 256,000-token maximum output. It accepts image, text, and video inputs and returns text. It supports reasoning mode and tool calling. The model is not open-weights. Pricing starts at $0.8906 per million input tokens and $4.45 per million output tokens, with cached input at $0.1781 per million tokens.

Against Seed 2.0 Pro: input $0.475 to $0.8906, output $2.37 to $4.45, cached input $0.095 to $0.1781.

• ·Accepts image, text, and video inputs
• ·Supports reasoning mode for complex tasks
• ·Supports tool calling for agent workflows
• ·256k token context and output windows
• ·Designed for coding and multimodal reasoning

• Reach for it for complex multimodal reasoning
• Reach for it for coding tasks with large context
• Reach for it for agentic workflows with tool calling

1 host serve this model at the price above · the maker's documentation

The registry keeps the six most recent versions of a line. Older ones stay in the file and can be surfaced without a rebuild.

What is the context window?

256,000 tokens for both input and output.

Is the model open-weights?

No, it is not open-weights.

What is the pricing?

From $0.8906 per million input tokens and $4.45 per million output tokens, with cached input at $0.1781 per million tokens.