Choose ByteDance Seed: Seed 1.6 Flash if…
- cost matters at scale — it is 31% cheaper on a typical 3:1 input/output mix ($11.63 vs $17.75 a month for 50,000 support chats)
ByteDance Seed: Seed 1.6 Flash vs Qwen: Qwen3.5-9B (batch)
Neither wins outright: ByteDance Seed: Seed 1.6 Flash is the pick when cost matters at scale, Qwen: Qwen3.5-9B (batch) when you generate long outputs in one go.
Key numbers
| Spec | ByteDance Seed: Seed 1.6 Flash | Qwen: Qwen3.5-9B (batch) |
|---|---|---|
| Provider | Bytedance Seed | Qwen |
| Input price (per 1M tokens) | $0.07 | $0.17 |
| Output price (per 1M tokens) | $0.30 | $0.25 |
| Blended price (3:1 input/output) | $0.13 | $0.19 |
| Cheaper than … of all models we track | 76% | 70% |
| Context window | 262K tokens (~393 pages) | 262K tokens (~393 pages) |
| Larger context than … of all models | 48% | 48% |
| Max output per response | 33K tokens (~24,600 words) | 236K tokens (~176,900 words) |
| Input types | image, text, video | text, image, video |
| Output types | text | text |
| Free variant | No | No |
| Listed since | 2025-12-23 | 2026-03-10 |
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What it costs for real workloads
Monthly cost at list price for five common workloads. Token counts per unit are stated so you can scale them to your own traffic. A workload that does not fit a model's context window is marked rather than priced.
| Workload (per month) | ByteDance Seed: Seed 1.6 Flash | Qwen: Qwen3.5-9B (batch) | Difference |
|---|---|---|---|
| Customer-support chatbot 50,000 conversations — each a 6-turn conversation (1,500 in / 400 out tokens) | $11.63 | $17.75 | ByteDance Seed: Seed 1.6 Flash saves $6.13 |
| RAG search over documents 20,000 questions — each a question answered from ~8 retrieved passages (6,000 in / 500 out tokens) | $12.00 | $22.90 | ByteDance Seed: Seed 1.6 Flash saves $10.90 |
| Coding / tool-using agent 2,000 tasks — each a multi-step task with tool calls and file context (60,000 in / 6,000 out tokens) | $12.60 | $23.40 | ByteDance Seed: Seed 1.6 Flash saves $10.80 |
| Batch summarisation 10,000 documents — each a 6,000-word report summarised to a page (8,000 in / 600 out tokens) | $7.80 | $15.10 | ByteDance Seed: Seed 1.6 Flash saves $7.30 |
| Long-document analysis 500 documents — each a 150-page contract or codebase read in one pass (100,000 in / 2,000 out tokens) | $4.05 | $8.75 | ByteDance Seed: Seed 1.6 Flash saves $4.70 |
Capabilities side by side
| Capability | ByteDance Seed: Seed 1.6 Flash | Qwen: Qwen3.5-9B (batch) | What it lets you do |
|---|---|---|---|
| Tool / function calling | ✓ Yes | ✓ Yes | call your APIs and run agent loops |
| Structured output (JSON schema) | ✓ Yes | ✓ Yes | return JSON that validates against your schema |
| Reasoning / thinking mode | ✓ Yes | ✓ Yes | spend extra tokens thinking before answering hard problems |
| Image input | ✓ Yes | ✓ Yes | read screenshots, charts and scanned pages |
| Audio input | — | — | take speech or audio directly |
| File / PDF input | — | — | accept documents without your own parsing step |
| Image output | — | — | generate images, not just text |
| Built-in web search | — | — | answer from live web results |
| Seed (reproducible sampling) | — | — | repeat a generation for tests and evals |
| Log-probabilities | — | — | read token confidence for classification and scoring |
From each model's published parameters and input/output types. “—” means not advertised, not proven absent.
Price history
- ByteDance Seed: Seed 1.6 Flash: price unchanged since we started tracking it on 2026-03-10.
- Qwen: Qwen3.5-9B (batch): price unchanged since we started tracking it on 2026-08-29.
Which should you choose?
Choose Qwen: Qwen3.5-9B (batch) if…
- you generate long outputs in one go — up to 236K tokens (about 176,900 words) per response
Frequently asked questions
Is ByteDance Seed: Seed 1.6 Flash better than Qwen: Qwen3.5-9B (batch)?
Neither wins outright: ByteDance Seed: Seed 1.6 Flash is the pick when cost matters at scale, Qwen: Qwen3.5-9B (batch) when you generate long outputs in one go. In short: ByteDance Seed: Seed 1.6 Flash when cost matters at scale; Qwen: Qwen3.5-9B (batch) when you generate long outputs in one go.
Which is cheaper, ByteDance Seed: Seed 1.6 Flash or Qwen: Qwen3.5-9B (batch)?
ByteDance Seed: Seed 1.6 Flash is cheaper: $0.13 vs $0.19 per 1M tokens at a typical 3:1 input/output mix, 31% less. For 50,000 support conversations a month that is $11.63 against $17.75.
How much do ByteDance Seed: Seed 1.6 Flash and Qwen: Qwen3.5-9B (batch) cost per million tokens?
ByteDance Seed: Seed 1.6 Flash costs $0.07 per 1M input tokens and $0.30 per 1M output tokens; Qwen: Qwen3.5-9B (batch) costs $0.17 input and $0.25 output. Output tokens are billed separately, so long answers shift the gap.
Which has the bigger context window, ByteDance Seed: Seed 1.6 Flash or Qwen: Qwen3.5-9B (batch)?
Both take 262K tokens per request — roughly 393 pages of text.
Do ByteDance Seed: Seed 1.6 Flash and Qwen: Qwen3.5-9B (batch) support function calling and JSON output?
Tool calling — ByteDance Seed: Seed 1.6 Flash: yes, Qwen: Qwen3.5-9B (batch): yes. JSON-schema structured output — ByteDance Seed: Seed 1.6 Flash: yes, Qwen: Qwen3.5-9B (batch): yes.
Can ByteDance Seed: Seed 1.6 Flash or Qwen: Qwen3.5-9B (batch) read images?
Yes, both accept image input.
Is ByteDance Seed: Seed 1.6 Flash or Qwen: Qwen3.5-9B (batch) free to use?
No free variant is listed for either; both are pay-per-token.
What is the maximum output length of ByteDance Seed: Seed 1.6 Flash and Qwen: Qwen3.5-9B (batch)?
ByteDance Seed: Seed 1.6 Flash can write up to 33K tokens (about 24,600 words) per response; Qwen: Qwen3.5-9B (batch) up to 236K (about 176,900 words).
When were ByteDance Seed: Seed 1.6 Flash and Qwen: Qwen3.5-9B (batch) released?
ByteDance Seed: Seed 1.6 Flash was listed on 2025-12-23; Qwen: Qwen3.5-9B (batch) on 2026-03-10.
About the two models
ByteDance Seed: Seed 1.6 Flash
Seed 1.6 Flash is an ultra-fast multimodal deep thinking model by ByteDance Seed, supporting both text and visual understanding. It features a 256k context window and can generate outputs of...
Full ByteDance Seed: Seed 1.6 Flash specs →Qwen: Qwen3.5-9B (batch)
Qwen3.5-9B is a multimodal foundation model from the Qwen3.5 family, designed to deliver strong reasoning, coding, and visual understanding in an efficient 9B-parameter architecture. It uses a unified vision-language design...
Full Qwen: Qwen3.5-9B (batch) specs →