Step 3.5 Flash vs Seed 2.0 Mini
Seed 2.0 Mini comes out ahead, 80 to 62 on our weighted score, and it is the cheaper option too.
StepFunStep 3.5 Flash
62/100- ECI—
- Price$0.10 / $0.30
- Context256K
- Our pick
ByteDance SeedSeed 2.0 Mini
80/100- ECI—
- Price$0.03 / $0.297
- Context256K
Add a model
Make it a three-way comparison.
Seed 2.0 Mini is our pick
Seed 2.0 Mini is the better all-round choice, scoring 80/100 against Step 3.5 Flash (62). It leads on price and inputs & features. 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 priceSeed 2.0 MiniSeed 2.0 Mini $0.097 · Step 3.5 Flash $0.15 per 1M tokens (3:1 blend)
- Longest contextAbout the sameStep 3.5 Flash 256,000 · Seed 2.0 Mini 256,000 tokens
- Widest inputsSeed 2.0 MiniStep 3.5 Flash: Text · Seed 2.0 Mini: Text, Images, Video
- Self-hostingStep 3.5 FlashPublishes downloadable weights
| Measure | Weight | Step 3.5 Flash | Seed 2.0 Mini |
|---|---|---|---|
| Price | 50% | 89 | 98 |
| Inputs & features | 30% | 35 | 80 |
| Context window | 20% | 36 | 36 |
| Overall | 100% | 62/100 | 80/100 |
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 | Step 3.5 FlashStepFun | Seed 2.0 MiniByteDance Seed |
|---|---|---|
| Capability | ||
| Capabilities Index (ECI) | — | — |
| ECI rank | — | — |
| Price per million tokens | ||
| Input | $0.10 | $0.03 (best) |
| Output | $0.30 | $0.297 (best) |
| Cached input | $0.02 | $0.0059 (best) |
| Blended (3:1) | $0.15 | $0.097 (best) |
| Long-context rate | Same rate | Over 32K: $0.059 / $0.594 |
| Price source | Official StepFun (Global) API | Official Volcengine Ark API |
| Limits | ||
| Context window | 256,000 tokens | 256,000 tokens |
| Max output | 256,000 tokens (best) | 32,000 tokens |
| Inputs and features | ||
| Text | Yes | Yes |
| Images | No | Yes |
| PDFs | No | No |
| Audio | No | No |
| Video | No | Yes |
| Reasoning | Yeslow · high | Yesminimal · low · medium · high · xhigh · max |
| Tool calling | Yes | Yes |
| Structured output | No | Yes |
| Availability | ||
| Weights | Open | Proprietary |
| API model ID | step-3.5-flash | doubao-seed-2-0-mini-260428 |
| API providers | 8 | 8 |
| Released | Jan 29, 2026 | Feb 14, 2026 |
| Knowledge cutoff | Jan 2025 | — |
What would a month cost?
Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.
- Step 3.5 Flash$1.60
- Seed 2.0 Mini$0.891
Which should you choose?
Which is better: Step 3.5 Flash or Seed 2.0 Mini?
Seed 2.0 Mini is the better all-round choice, scoring 80/100 against Step 3.5 Flash (62). It leads on price and inputs & features. 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, Step 3.5 Flash or Seed 2.0 Mini?
Seed 2.0 Mini is cheaper at $0.03 input / $0.297 output per million tokens (official Volcengine Ark API price). Step 3.5 Flash costs $0.10 input / $0.30 output per million tokens (official StepFun (Global) API price). At a typical mix of three input tokens to one output token, that is $0.097 per million tokens for Seed 2.0 Mini versus $0.15 for Step 3.5 Flash (1.6× as much).
Which scores higher on benchmarks?
There is no independent benchmark that covers both models yet. Step 3.5 Flash has not been scored yet and Seed 2.0 Mini has not been scored yet.
Which is better for coding?
There are no published SWE-bench Verified results for Step 3.5 Flash and Seed 2.0 Mini 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?
Step 3.5 Flash and Seed 2.0 Mini share the same 256,000-token context window. Maximum output per response: Step 3.5 Flash up to 256,000, Seed 2.0 Mini up to 32,000 tokens.
Which can read images, PDFs, audio or video?
Step 3.5 Flash accepts text; Seed 2.0 Mini accepts text, images and video. Seed 2.0 Mini handles the widest range of inputs.
Are any of these open source?
Step 3.5 Flash publishes its weights and can be self-hosted; Seed 2.0 Mini is proprietary.
Which is newer?
Seed 2.0 Mini is the newest, released Feb 14, 2026. Step 3.5 Flash came out Jan 29, 2026. Knowledge cutoff: Step 3.5 Flash Jan 2025.
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.
