Seed 2.1 Pro (Reasoning)
by ByteDance
Seed 2.1 Pro (Reasoning) is a reasoning model from ByteDance, released on June 24, 2026. It ranks #28 of 220 models by Intelligence Score with a score of 45.8.
ByteDance's flagship next-generation agent model built for real-world productivity. A deep-thinking model with strong demand understanding, long-horizon planning, and continuous self-repair, it delivers reliable end-to-end results across complex coding, long-chain agents, and multi-step engineering workflows. Seed 2.1 Pro also advances knowledge, reasoning, and multimodal understanding, with SOTA results across several video understanding benchmarks. Served via Volcano Engine as Doubao-Seed-2.1-pro.
Key specs
| Provider | ByteDance |
|---|---|
| Release date | 2026-06-24 |
| License | proprietary |
| Intelligence Score | 45.8 |
| Coding index | 32 |
Quick answers
Is Seed 2.1 Pro (Reasoning) open source?
No. Seed 2.1 Pro (Reasoning) is a proprietary model from ByteDance (proprietary license).
When was Seed 2.1 Pro (Reasoning) released?
ByteDance released Seed 2.1 Pro (Reasoning) on June 24, 2026.
How does Seed 2.1 Pro (Reasoning) compare to Claude Opus 5.5 (Reasoning)?
Seed 2.1 Pro (Reasoning) scores 45.8 on the Intelligence Score versus 60.5 for Claude Opus 5.5 (Reasoning), the current #1.
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- Seed 2.0 Code (Reasoning) — ByteDance