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Comparison · 2 models · Updated Oct 4, 2026

Step 3.7 Flash vs Seed 2.1 Turbo

Step 3.7 Flash comes out ahead, 62 to 57 on our weighted score, and it is the cheaper option too.

  1. Our pick

    StepFun

    Step 3.7 Flash

    Released May 29, 2026

    62/100
    • ECI—
    • Price$0.185 / $1.11
    • Context256K
    Full specs Remove Step 3.7 Flash

  2. ByteDance Seed

    Seed 2.1 Turbo

    Released Jun 23, 2026

    57/100
    • ECI—
    • Price$0.445 / $2.23
    • Context256K
    Full specs Remove Seed 2.1 Turbo

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Step 3.7 Flash is our pick

Step 3.7 Flash is the better all-round choice, scoring 62/100 against Seed 2.1 Turbo (57). It leads on price. Seed 2.1 Turbo wins on 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 priceStep 3.7 FlashStep 3.7 Flash $0.416 · Seed 2.1 Turbo $0.891 per 1M tokens (3:1 blend)
  • Longest contextAbout the sameStep 3.7 Flash 256,000 · Seed 2.1 Turbo 256,000 tokens
  • Widest inputsSame inputsStep 3.7 Flash: Text, Images, Video · Seed 2.1 Turbo: Text, Images, Video
  • Self-hostingStep 3.7 FlashPublishes downloadable weights
How the score is built
MeasureWeightStep 3.7 FlashSeed 2.1 Turbo
Price50%6852
Inputs & features30%7080
Context window20%3636
Overall100%62/10057/100

Left out because at least one model lacks the data: capability. The remaining weights were rescaled.

02 — Side by side

Every spec in one table

Highlighted cells lead their row. Dashes mean the data is not published.

Step 3.7 Flash vs Seed 2.1 Turbo specifications side by side
SpecificationStep 3.7 FlashStepFunSeed 2.1 TurboByteDance Seed
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.185 (best)$0.445
Output$1.11 (best)$2.23
Cached input$0.037 (best)$0.089
Blended (3:1)$0.416 (best)$0.891
Long-context rateSame rateSame rate
Price sourceOfficial StepFun (Global) APIOfficial Volcengine Ark API
Limits
Context window256,000 tokens256,000 tokens
Max output256,000 tokens256,000 tokens
Inputs and features
TextYesYes
ImagesYesYes
PDFsNoNo
AudioNoNo
VideoYesYes
ReasoningYeslow · medium · highYesminimal · low · medium · high · xhigh · max
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenProprietary
API model IDstep-3.7-flashdoubao-seed-2-1-turbo-260628
API providers18 (best)4
ReleasedMay 29, 2026Jun 23, 2026
Knowledge cutoffMar 1, 2026—
03 — Cost

What would a month cost?

Enter your expected volume in millions of tokens. List prices only; caching and batch discounts would lower these.

  • Step 3.7 Flash$4.07
  • Seed 2.1 Turbo$8.91
04 — Questions

Which should you choose?

Which is better: Step 3.7 Flash or Seed 2.1 Turbo?

Step 3.7 Flash is the better all-round choice, scoring 62/100 against Seed 2.1 Turbo (57). It leads on price. Seed 2.1 Turbo wins on 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 3.7 Flash or Seed 2.1 Turbo?

Step 3.7 Flash is cheaper at $0.185 input / $1.11 output per million tokens (official StepFun (Global) API price). Seed 2.1 Turbo costs $0.445 input / $2.23 output per million tokens (official Volcengine Ark API price). At a typical mix of three input tokens to one output token, that is $0.416 per million tokens for Step 3.7 Flash versus $0.891 for Seed 2.1 Turbo (2.1× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Step 3.7 Flash has not been scored yet and Seed 2.1 Turbo has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Step 3.7 Flash and Seed 2.1 Turbo 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 3.7 Flash and Seed 2.1 Turbo share the same 256,000-token context window. Maximum output per response: Step 3.7 Flash up to 256,000, Seed 2.1 Turbo up to 256,000 tokens.

Which can read images, PDFs, audio or video?

Step 3.7 Flash accepts text, images and video; Seed 2.1 Turbo accepts text, images and video. They handle the same number of input types.

Are any of these open source?

Step 3.7 Flash publishes its weights and can be self-hosted; Seed 2.1 Turbo is proprietary.

Which is newer?

Seed 2.1 Turbo is the newest, released Jun 23, 2026. Step 3.7 Flash came out May 29, 2026. Knowledge cutoff: Step 3.7 Flash Mar 1, 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.

05 — Keep comparing

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