Qwen3.5 Flash vs Seed 2.0 Code
Qwen3.5 Flash comes out ahead, 79 to 57 on our weighted score, and it is the cheaper option too.
- Our pick
Alibaba (Qwen)Qwen3.5 Flash
79/100- ECI144.0
- Price$0.10 / $0.40
- Context1M
ByteDance SeedSeed 2.0 Code
57/100- ECI—
- Price$0.475 / $2.37
- Context262K
Add a model
Make it a three-way comparison.
Qwen3.5 Flash is our pick
Qwen3.5 Flash is the better all-round choice, scoring 79/100 against Seed 2.0 Code (57). It leads on price and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
- CapabilityNot enough dataNo independent benchmark covers every model here yet
- Lowest priceQwen3.5 FlashQwen3.5 Flash $0.175 · Seed 2.0 Code $0.95 per 1M tokens (3:1 blend)
- Longest contextQwen3.5 FlashQwen3.5 Flash 1,000,000 · Seed 2.0 Code 262,144 tokens
- Widest inputsSame inputsQwen3.5 Flash: Text, Images, Video · Seed 2.0 Code: Text, Images, Video
- Self-hostingNo open weightsBoth are available only through APIs
| Measure | Weight | Qwen3.5 Flash | Seed 2.0 Code |
|---|---|---|---|
| Price | 50% | 86 | 51 |
| Inputs & features | 30% | 80 | 80 |
| Context window | 20% | 60 | 37 |
| Overall | 100% | 79/100 | 57/100 |
Left out because at least one model lacks the data: capability. The remaining weights were rescaled.
Every spec in one table
Highlighted cells lead their row. Dashes mean the data is not published.
| Specification | Qwen3.5 FlashAlibaba (Qwen) | Seed 2.0 CodeByteDance Seed |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | 144.0 | — |
| ECI rank | #82 of 148 | — |
| GPQA DiamondGraduate-level science questions | 82.3% | — |
| FrontierMath Tiers 1–3Research-level mathematics | 18.3% | — |
| OTIS Mock AIME 2024–2025Competition mathematics | 84.4% | — |
| SimpleQA VerifiedShort factual questions | 20.3% | — |
| Price per million tokens | ||
| Input | $0.10 (best) | $0.475 |
| Output | $0.40 (best) | $2.37 |
| Cached input | $0.01 (best) | $0.095 |
| Blended (3:1) | $0.175 (best) | $0.95 |
| Long-context rate | Same rate | Over 32K: $0.712 / $3.56 |
| Price source | Official Alibaba API | Official Volcengine Ark API |
| Limits | ||
| Context window | 1,000,000 tokens (best) | 262,144 tokens |
| Max output | 65,536 tokens | 131,072 tokens (best) |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | Yes | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | Yes | Yes |
| Reasoning | Yes | Yesminimal · low · medium · high · xhigh · max |
| Tool calling | Yes | Yes |
| Structured output | Yes | Yes |
| Availability | ||
| Weights | Proprietary | Proprietary |
| API model ID | qwen3.5-flash | doubao-seed-2-0-code-preview-260215 |
| API providers | 8 | 10 (best) |
| Released | Feb 23, 2026 | Feb 14, 2026 |
| Knowledge cutoff | — | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Qwen3.5 Flash$1.80
- Seed 2.0 Code$9.50
Which should you choose?
Which is better: Qwen3.5 Flash or Seed 2.0 Code?
Qwen3.5 Flash is the better all-round choice, scoring 79/100 against Seed 2.0 Code (57). It leads on price and context window. The score weighs price 50%, inputs & features 30%, context window 20%. None of the shared benchmarks cover every model here yet, so capability is left out of this verdict.
Which is cheaper, Qwen3.5 Flash or Seed 2.0 Code?
Qwen3.5 Flash is cheaper at $0.10 input / $0.40 output per million tokens (official Alibaba API price). Seed 2.0 Code costs $0.475 input / $2.37 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $0.175 per million tokens for Qwen3.5 Flash versus $0.95 for Seed 2.0 Code (5.4× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Qwen3.5 Flash has an ECI of 144.0 and Seed 2.0 Code has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Qwen3.5 Flash and Seed 2.0 Code yet, so there is no like-for-like coding score. Test both on a sample of your own tasks. Both support tool calling for agent workflows.
Which has the bigger context window?
Qwen3.5 Flash has the largest context window at 1,000,000 tokens, against 262,144 for Seed 2.0 Code. Maximum output per response: Qwen3.5 Flash up to 65,536, Seed 2.0 Code up to 131,072 tokens.
Which can read images, PDFs, audio or video?
Qwen3.5 Flash accepts text, images and video; Seed 2.0 Code accepts text, images and video. They handle the same number of input types.
Are any of these open source?
No. Qwen3.5 Flash and Seed 2.0 Code are proprietary and only available through APIs and apps.
Which is newer?
Qwen3.5 Flash is the newest, released Feb 23, 2026. Seed 2.0 Code came out Feb 14, 2026.
How do you decide the winner?
Each model gets a 0–100 score on capability (50%, independent benchmark results); price (25%, blended price per million tokens (3 input : 1 output), log scale); inputs & features (15%, image, PDF, audio and video input, tool calling, structured output and reasoning); context window (10%, maximum tokens per request, log scale). Dimensions missing for any model are dropped and the remaining weights rescaled, so every model is judged on the same evidence. Specs and prices come from public model listings and the labs’ own API pages; capability scores come from independent benchmark runs. Data updated Oct 4, 2026.
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