ByteDance releases Seed2.1

Background

Seed2.1 follows Seed2.0, the series ByteDance released in February 2026. The newer series is aimed at practical productivity work.

What happened

On 23 June 2026 ByteDance Seed announced Seed2.1, available to users of Doubao and Volcano Engine.^[1]

Models

The series has Pro and Turbo models, both aimed at real productivity work.^[2]

What changed

Seed2.1 builds on Seed2.0 and aims for more reliable answers and more consistent delivery, which means the same kind of task should produce results of similar quality each time.^[1]

Key results

Seed2.1 Pro scored 87.0 on BeyondAIME and 71.0 on Terminal Bench 2.1 in ByteDance's tests. BeyondAIME is a mathematics benchmark, and Terminal Bench tests tasks carried out in a command-line environment.^[2]

Computer-use agents

Reinforcement learning cut the number of steps a computer-use agent needs per task by 16% on average.^[1] A computer-use agent operates software on a screen, so fewer steps per task means it finishes the same work with fewer actions.

Code

A Seed2.1 Preview ranked 8th on the Code Arena frontend leaderboard.^[1]

Agents that operate a computer work by looking at the screen and taking actions one step at a time. Each step costs time and computing, so reducing the steps per task improves both speed and cost. A preview version is an early release used to gather feedback before the final models are announced.

Users choosing between tiers usually weigh capability against response time and cost, and the right choice depends on how demanding the task is. A preview version is often judged by its placement on one leaderboard, so that placement describes a snapshot rather than the final release.

Significance

The announcement stressed reliability and productivity. Its results are ByteDance's own figures, and the leaderboard placement describes a preview version rather than the final models.