ByteDance: Seed 1.8
bytedance/seed-1.8
Access Seed 1.8 from ByteDance using Puter.js AI API.
Get Started// npm install @heyputer/puter.js
import { puter } from '@heyputer/puter.js';
puter.ai.chat("Explain quantum computing in simple terms", {
model: "bytedance/seed-1.8"
}).then(response => {
document.body.innerHTML = response.message.content;
});
<html>
<body>
<script src="https://js.puter.com/v2/"></script>
<script>
puter.ai.chat("Explain quantum computing in simple terms", {
model: "bytedance/seed-1.8"
}).then(response => {
document.body.innerHTML = response.message.content;
});
</script>
</body>
</html>
# pip install openai
from openai import OpenAI
client = OpenAI(
base_url="https://api.puter.com/puterai/openai/v1/",
api_key="YOUR_PUTER_AUTH_TOKEN",
)
response = client.chat.completions.create(
model="bytedance/seed-1.8",
messages=[
{"role": "user", "content": "Explain quantum computing in simple terms"}
],
)
print(response.choices[0].message.content)
curl https://api.puter.com/puterai/openai/v1/chat/completions \
-H "Content-Type: application/json" \
-H "Authorization: Bearer YOUR_PUTER_AUTH_TOKEN" \
-d '{
"model": "bytedance/seed-1.8",
"messages": [
{"role": "user", "content": "Explain quantum computing in simple terms"}
]
}'
Model Card
Seed 1.8 is an agentic multimodal model from ByteDance's Seed team that combines search, code, and GUI agent capabilities in a single system. It accepts text, image, and video input and supports three thinking modes that adjust reasoning depth to task complexity.
ByteDance reports 67.6 on BrowseComp-en for web search tasks and 87.8 on VideoMME for long-form video understanding, and says the model approaches Gemini 3 Pro on most multimodal tasks while surpassing it on BrowseComp-en.
With a 256K context window and tool calling, it fits multi-step agent workflows such as web research, code generation, and GUI automation over screenshots.
Context Window 256K
tokens
Max Output 64K
tokens
Input Cost $0.25
per million tokens
Output Cost $2
per million tokens
Input text, image, video
modalities
Tool Use Yes
Release Date Dec 18, 2025
Model Playground
Try Seed 1.8 instantly in your browser.
This playground uses the Puter.js AI API — no API keys or setup required.
More AI Models From ByteDance
Seed 2.1 Turbo
Seed 2.1 Turbo is the faster, lower-cost variant in ByteDance's Seed 2.1 family, a model line built for coding, long-horizon agent tasks, and multimodal understanding. It accepts text and image input, has a 256K context window, and supports function calling in an OpenAI-compatible format, so existing tool-use pipelines port over with little change. ByteDance positions it for high-volume production workloads such as agent pipelines, coding assistance, and document processing, and prices it at roughly half the cost of Seed 2.1 Pro. The company reports performance close to the Pro version and comparable to GPT-5.5 on coding and agent tasks, though no independently verified benchmark scores for Turbo were published at launch. Choose it when volume and cost drive the decision rather than peak capability; Seed 2.1 Pro remains the stronger option for the hardest tasks.
ChatSkylark Pro SC 260215
Skylark Pro SC 260215 is a dated snapshot of Skylark Pro, the chat model family ByteDance serves through its BytePlus ModelArk platform. The 260215 identifier corresponds to a February 15, 2026 build. BytePlus positions Skylark Pro as its flagship model for complex question answering, summarization, creative writing, and role-playing. The model line also supports function calling and structured output through the API. This snapshot has a 128,000-token context window and returns up to 12,000 output tokens per response. Pinning a dated snapshot like this one keeps behavior stable across requests, which is useful when a workload has been tuned against a specific build rather than a rolling alias.
ChatSeed 2.0 Code
Seed 2.0 Code is ByteDance's dedicated coding model, released with the Seed 2.0 family in February 2026. It is built for agentic software work rather than autocomplete, with a stated focus on decomposing tasks into plans and revising those plans as work progresses, which suits multi-step feature implementation and bug diagnosis and repair. The model accepts image input alongside text, so it can read design mockups, screenshots, and charts and generate code from them. ByteDance cites high-precision text extraction and chart understanding as part of its multimodal perception. It has a 256K context window and up to 128K output tokens. ByteDance has not published benchmark scores for the Code variant. The same model powers coding in TRAE, ByteDance's AI IDE.
Frequently Asked Questions
You can access Seed 1.8 by ByteDance through Puter.js AI API. Include the library in your web app or Node.js project and start making calls with just a few lines of JavaScript — no backend and no configuration required. You can also use it with Python or cURL via Puter's OpenAI-compatible API.
Yes, it is free if you're using it through Puter.js. With the User-Pays Model, you can add Seed 1.8 to your app at no cost — your users pay for their own AI usage directly, making it completely free for you as a developer.
| Price per 1M tokens | |
|---|---|
| Input | $0.25 |
| Output | $2 |
Seed 1.8 was created by ByteDance and released on Dec 18, 2025.
Seed 1.8 supports a context window of 256K tokens. For reference, that is roughly equivalent to 512 pages of text.
Seed 1.8 can generate up to 64K tokens in a single response.
Seed 1.8 accepts the following input types: text, image, video. It produces: text.
Yes, Seed 1.8 supports tool use (function calling), allowing it to interact with external tools, APIs, and data sources as part of its response flow.
Yes — the Seed 1.8 API works with any JavaScript framework, Node.js, or plain HTML through Puter.js. Just include the library and start building. See the documentation for more details.
Get started with Puter.js
Add Seed 1.8 to your app without worrying about API keys or setup.
Read the Docs View Tutorials