Doubao Seed 1.8
ByteDance's cost-efficient multimodal agent model, tuned for the Volcano Engine ecosystem.
About
Doubao Seed 1.8 is ByteDance Seed's multimodal agent model, released December 2025 and positioned as the cost-efficient middle tier of the Doubao lineup — daily multimodal chat and general vision work, sitting below the Seed 2.0 Pro flagship. It is optimized for multimodal agents and complex instruction following, and it powers the voice-driven AI features of the limited-edition Nubia M153 smartphone ByteDance co-developed with ZTE. ByteDance reports the Doubao family averaging over 50 trillion tokens of daily usage, with Volcano Engine holding roughly half of China's AI-model public cloud market per IDC.
The Seed team's reported numbers are all provider-claimed: 67.6 on the BrowseComp agent benchmark, 87.0 on VideoMME, 62.0 on VLMsAreBiased, 25.8 on MMSiBench, and SOTA on 5 of 6 MotionBench tasks. Access is through Volcano Engine's Ark platform with an OpenAI-compatible chat completions API.
Specs
Context window
Pricing
Free quota
API access
Weights
Released
Benchmarks
Provider-reported (ByteDance Seed team): BrowseComp 67.6, VideoMME 87.0, VLMsAreBiased 62.0, MMSiBench 25.8, MotionBench SOTA on 5/6 tasks.
Independent: no third-party reproduction found.
Provider-reported unless a source says otherwise. Benchmarks are marketing-adjacent by nature — treat them as directional.
Use cases
Trust score — 7/10
Release confirmed by ByteDance's Seed team site and independent press with consistent specs. Docked for: (1) every benchmark figure is provider-reported with no independent reproduction; (2) proprietary with no weights; (3) international API access requires Volcano Engine registration, which is friction-heavy outside China.