Overview
Seed 2.1 Pro is the flagship model in ByteDance's Doubao Seed 2.1 family, announced at the Volcano Engine FORCE conference on June 24, 2026 and offered through Volcano Engine's API alongside the smaller Seed 2.1 Turbo. It is positioned by the Seed team as an agent-first model that targets long-horizon productivity work across coding, tool use, and multimodal reasoning rather than single-turn Q&A.
The Seed team publishes a comparison suite pitting Seed 2.1 Pro directly against Claude Opus 4.7, GPT-5.5 and Gemini 3.1 Pro across knowledge, reasoning, code, terminal use, spatial reasoning, long-video understanding and streaming perception benchmarks. Seed 2.1 Pro takes the top slot on MathVision with tools (94.5), MMMU-Pro with tools (82.7), WorldVQA (53.0), ZEROBench with tools (22.0), BabyVision (73.7), CharXiv-RQ with tools (86.4), ERQA (72.0), VideoMME (89.2), TOMATO (79.5), Minerva (70.7) and OVOBench (80.7), while remaining competitive on Terminal Bench 2.1, Workspace Bench and NL2Repo-Bench. Seed 2.1 Turbo is the same generation's smaller, faster sibling.
Seed 2.1 Pro is served via ByteDance's Volcano Engine API (model id doubao-seed-2-1-pro-260628) and powers the Doubao assistant. Weights are not published — Seed 2.1 is a proprietary, API-only line.
| Released | 2026-06-24 |
|---|---|
| License | Proprietary |
| Weights | API only |
| Modalities | Text, Vision, Video |
| Status | Generally available |
Benchmarks
Seed 2.1 Pro vs Claude Opus 4.7, GPT-5.5 and Gemini 3.1 Pro across the benchmark suite published on the ByteDance Seed 2.1 page. Blank cells reflect scores the maker did not report for that model.
| Benchmark | Seed 2.1 Pro | Seed 2.1 Turbo | Claude Opus 4.7 | GPT-5.5 | Gemini 3.1 Pro |
|---|---|---|---|---|---|
| KINA | 48.3% | 46.6% | 46.7% | 52.6% | 53.2% |
| SuperGPQA | 70.8% | 67.4% | 68.5% | 72.7% | 76.6% |
| BeyondAIMER | 87% | 88% | 79% | 91% | 90% |
| Workspace Bench | 53% | 54.7% | 55.1% | 58.7% | 32.8% |
| Agent Startup Bench | 68.8% | 54% | 62.3% | 68.1% | 45.7% |
| xDailyBench | 61% | 56.4% | 69% | 73% | 35.2% |
| NL2Repo-Bench | 47% | 43.7% | 58.2% | 45.1% | 33.4% |
| ProgramBench | 50.3% | 49.4% | 52.1% | 65.9% | 40.7% |
| Terminal Bench 2.1 | 71% | 67.6% | 71.7% | 73.8% | 70.7% |
| SWE-Atlas | 35.2% | 30.6% | 38.7% | 44.7% | 23.6% |
| MathVision (with tool) | 94.5% | 92.7% | 83.1% | 92.2% | 89.2% |
| MMMU-Pro (with tool) | 82.7% | 82.2% | 74% | 81.2% | 80.5% |
| WorldVQA | 53% | 48.6% | 35.9% | 34.6% | 44.3% |
| ZEROBench (with tool) | 22% | 20% | 8% | 13% | 12% |
| BabyVision | 73.7% | 62.9% | 22.2% | 55.9% | 54.4% |
| CharXiv-RQ (with tool) | 86.4% | 83.6% | 82.1% | 83.2% | 83.5% |
| ERQA | 72% | 71.3% | 52.5% | 64.5% | 70.8% |
| MMLongBench-128K | 78.3% | 76.9% | — | — | 70.7% |
| VideoMME | 89.2% | 89% | — | — | 86.7% |
| TOMATO | 79.5% | 56.8% | — | — | 60.4% |
| Minerva | 70.7% | 65.9% | — | — | 63.5% |
| OVOBench | 80.7% | 79.2% | — | — | 64.1% |
| VideoSimpleQA | 76.4% | 71.4% | — | — | 70% |
This model's scores
- MathVision (with tool)94.5%
- MMMU-Pro (with tool)82.7%
- VideoMME89.2%
- Terminal Bench 2.171%
- BeyondAIMER87%
- BabyVision73.7%
- MMLongBench-128K78.3%
Scores on a 0–100 scale (25-point gridlines); higher is better. Each benchmark links to its published source.
Strengths
- Top scores on the maker's published MathVision-with-tool, VideoMME and BabyVision benchmarks
- Multimodal input across text, images and long video (up to MMLongBench-128K)
- Agent-tuned for tool use, long-horizon coding and terminal workflows
- Available through Doubao and Volcano Engine's public API
Best for
- Agentic coding and terminal automation via Volcano Engine
- Multimodal reasoning over documents, infographics and video
- Long-video understanding, streaming perception and video Q&A
- Integration into Doubao-based productivity assistants
How to access
| Provider | Model ID |
|---|---|
| Volcano Engine (Doubao) ↗ | doubao-seed-2-1-pro-260628 |
FAQ
When was Seed 2.1 Pro released?
ByteDance's Seed team officially announced Seed 2.1 on June 23, 2026, and Seed 2.1 Pro and Seed 2.1 Turbo were unveiled at the Volcano Engine FORCE conference on June 24, 2026. Access is offered through the Doubao assistant and Volcano Engine's API.
Are Seed 2.1 weights available?
No. Seed 2.1 Pro is a proprietary, API-only model. ByteDance serves it through Volcano Engine (Doubao) and does not publish open weights for the Seed line.
What benchmarks does the Seed team publish for Seed 2.1 Pro?
The official Seed 2.1 page reports scores across knowledge (KINA 48.3, SuperGPQA 70.8), reasoning (BeyondAIMER 87.0), agentic/office work (Workspace Bench 53.0, Agent Startup Bench 68.8, xDailyBench 61.0), coding (NL2Repo-Bench 47.0, ProgramBench 50.3, SWE-Atlas 35.2, Terminal Bench 2.1 71.0), and multimodal reasoning (MathVision with tool 94.5, MMMU-Pro with tool 82.7, VideoMME 89.2, WorldVQA 53.0, BabyVision 73.7), all directly compared against Claude Opus 4.7, GPT-5.5 and Gemini 3.1 Pro.
How does Seed 2.1 Pro compare with Seed 2.1 Turbo?
Seed 2.1 Pro is the flagship member of the Seed 2.1 family; Seed 2.1 Turbo is a smaller, faster sibling in the same generation. On the Seed team's published comparison table, Pro leads Turbo on most benchmarks, while Turbo trades a small quality drop for cheaper, faster inference.