Seed 1.6
Language modelAPI only
Seed 1.6
ByteDance
- Released
- June 15, 2025
- Data date
- September 8, 2026
- Predecessor
- Seed 1.5 (Official documentation)
- Price
- Input · Output / 1M tokens
Seed 1.6 is ByteDance’s multimodal deep-thinking model with 230B total parameters, 23B active parameters, and 256K tokens of context. Its technical description highlights adaptive thinking time, AdaCoT, and GUI-agent use. The model can therefore vary the amount of internal planning between a direct answer and a more involved task.
Seed 1.6 is proprietary and API-only. Images and video are supported on the input side, while output remains text. There is no released checkpoint for local experiments, so the documented access path is BytePlus or the Volcano interface.
Specifications and access
| Specification | Value and source |
|---|---|
| Weights | ProprietarySource |
| Access | APISource |
| Parameters | 230BSource |
| Active parameters | 23BSource |
| Context window | 256,000 tokensSource |
| Notes | Multimodal deep-thinking model with a 256K context window; 230B total parameters, 23B active (MoE).Source |
| Reasoning mode | Deep thinking can be disabled with the thinking parameter. The documentation names seed-1-6-250915 and seed-1-6-250615. (retrieved 2026-09-22)Source |
| Release | 2025-06-15Source |
| License | proprietary BytePlus termsSource |
| API model ID | seed-1-6-250915Source |
Our tests
SVG short test
One SVG prompt and fixed output settings. Captures are shown only with 0 reported reasoning tokens or documented lack of reasoning controls. Identical test conditions do not make the models' internal compute identical.
Earlier tests
Pelican on a bicycle
A community classic for free-form SVG drawing.
Seed 1.6
Reasoning (requested): high
Current attempt
- Run date
- Oct 1, 2026
- API provider
- openrouter
- Requested API model
- bytedance-seed/seed-1.6
- API model reported in response
- bytedance-seed/seed-1.6
- Reasoning setting
- high
- Pinned endpoint
- Seed | bytedance-seed/seed-1.6-20250625
- Temperature
- Provider default
- Token limit including reasoning
- 8,192 tokens
- Test protocol
- community-visual-tests-v1
- Technical checks
- Passed, not a quality rating
- Response time
- 67.6 s
Visually reviewed. This individual test does not establish overall model quality.
Prompt and test conditions
Generate an SVG of a pelican riding a bicycle
Token limit including reasoning: 8,192 tokens
Task origin (Simon Willison)Popularity
12.7 / 100
Predecessor and successor
Sources and data date
| Type | Evidence and data date |
|---|---|
| Price | Base API prices without caching or batch discounts. Higher context tiers and other rates are listed under Costs. |
| Research status | Research date September 8, 2026. 5 source URLs checked. This documents the inspected sources, not an exhaustive inventory of every publication. |
| Not found in the inspected sources | parameters-billions Original wording No exact value located in the checked primary model card/API documentation. |
| Not found in the inspected sources | active-parameters-billions Original wording No exact value located in the checked primary model card/API documentation. |
| Not found in the inspected sources | knowledge-cutoff Original wording No exact value located in the checked primary model card/API documentation. |
| Unresolved | profile-benchmarks Original wording The official Seed1.6 release page distinguishes Seed1.6 Base, Seed1.6-Thinking, and Seed1.6 (Adaptive CoT), but its benchmark tables are image-only and the linked CDN images were unavailable during retrieval. The official Seed repository publishes Base and Thinking comparison columns, not the exact Seed1.6 API model seed-1-6-250915, so those scores are not attributed here. |
| Unresolved | AA benchmark rows Original wording No exact Artificial Analysis model page located in the checked public sitemap. |
| Not published | exact-version-quality-benchmarks Note ByteDance's public Seed1.6 benchmark discussion names Seed1.6-Thinking and Seed1.6 (Adaptive CoT) as distinct post-training variants; the reviewed numeric evidence was not attributable to this catalog's generic seed-1-6 endpoint. No score is assigned. |
| Additional source | Model metadata · ByteDance Seed 1.6 technical overview · Editorial description reviewed October 2, 2026 |
| Additional source | Context window data (retrieved September 22, 2026) · BytePlus Seed 1.6 documentation · Editorial description reviewed October 2, 2026 |
| Additional source | Model metadata (retrieved September 8, 2026) |
| Additional source | ByteDance Seed 1.6 model page · Editorial description reviewed October 2, 2026 |
| Additional source | OpenRouter: Popularity index (derived), CC BY 4.0 |
| Additional source | Vercel AI Gateway: Popularity index (derived), CC BY 4.0 |
| Additional source | Creative Commons Attribution 4.0 |