Seed 1.8
by ByteDance SeedChat
ByteDance Seed model for multimodal reasoning, long-context analysis, and agent workflows
- Context
- 256K tokens
- Max output
- 64,000 tokens
- Released
- 2025-12-18
- Weights
- Closed
bytedance-seed/seed-1-8-251228 · also seen as doubao-seed-1-8-251228, bytedance/seed-1-8-251228
Specifications
Full facts as recorded, incl. what is unknown.
- Released
- 2025-12-18
- Weights
- Closed
- Input
- Text, Image
- Output
- Text
- Context window
- 256,000 max across endpoints
- Max output
- 64,000
- Providers
- 1 + 2 gateways, not counted as providers
- Epoch Capabilities Index
- not evaluated
- Direct price range
- $0.119 in · $1.19 out per 1M tokens · from its one provider
More details
- Last updated
- 2025-12-28
- Knowledge cutoff
Capabilities
Across all endpoints: supported if any endpoint supports it.
- Tool calling
- Parallel toolsunknown
- Structured output
- Reasoning
- Image input
- PDF input
- Audio input
- Audio outputunknown
- Video input
- Prompt cachingunknown
- Web searchunknown
- Computer useunknown
- System messagesunknown
- Assistant prefillunknown
- Temperature
- Streamingunknown
- Attachments
Endpoints
One row per provider and variant; gateways are listed separately.
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Price history
Atom feedCheapest direct price, USD per 1M tokens, 19 Oct 2026 to 20 Oct 2026. Steps mark the pipeline run that saw the change.
Input price history: no headline price from 19 Oct 2026, $0.119 from 19 Oct 2026.
Output price history: no headline price from 19 Oct 2026, $1.19 from 19 Oct 2026.
Show as table
| From (UTC) | Input | Output | Cheapest at |
|---|---|---|---|
| 19 Oct 2026, 16:56 | $0.119 | $1.19 | Volcengine Ark |
| 19 Oct 2026, 14:54 | — | — | none |
Tracked from 19 Oct 2026. Headline-eligible direct prices only, so a price the sanity check flags never draws a spike. Series as JSON
Cost calculator
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Similarly priced models
Blended rate per 1M tokens, each at its own cheapest provider (10M input : 2M output mix).
| Model | Blended/1M | In/1M | Out/1M | Context | vs Seed 1.8 |
|---|---|---|---|---|---|
| Seed 2.0 LiteByteDance Seed | $0.542 | $0.25 | $2.00 | 131K | +0% |
| Seed 1.6ByteDance Seed | $0.542 | $0.25 | $2.00 | 256K | +0% |
| Seed 1.6 (250615)ByteDance Seed | $0.542 | $0.25 | $2.00 | 256K | +0% |
| Seed 1.6 (250915)ByteDance Seed | $0.542 | $0.25 | $2.00 | 256K | +0% |
| Qwen3.6 27BAlibaba (Qwen) | $0.543 | $0.203 | $2.24 | 262K | +0% |
| Qwen3 MaxAlibaba (Qwen) | $0.538 | $0.359 | $1.43 | 262K | −1% cheaper |
| Llama 3 70B InstructMeta | $0.548 | $0.51 | $0.74 | 8.2K | +1% |
| Mixtral 8x7B Instruct v0.1Mistral AI | $0.533 | $0.488 | $0.758 | 32.8K | −2% cheaper |
More from ByteDance Seed
Newest ByteDance Seed models in the catalogue. All ByteDance Seed models
| Model | Released | Context | Listed price |
|---|---|---|---|
| Seedream 5.0 Flash | 2026-10-01 | — | unpriced |
| Seed Audio 1.0 | 2026-09-25 | — | unpriced |
| Seedance 2.5 | 2026-08-07 | — | unpriced |
| Seedream 5.0 Pro | 2026-07-11 | — | unpriced |
| Seed 2.1 Turbo | 2026-06-23 | 262K | from $0.50 |
| Seed Evolving | 2026-06-23 | 256K | from $0.891 |
| Seed Character | 2026-06-23 | 256K | from $0.119 |
| Seed 2.1 Pro | 2026-06-23 | 256K | from $0.891 |