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Comparison · 2 models · Updated Oct 4, 2026

Seed 2.1 Turbo vs Solar Pro 4

Too close to call on our weighted score (Seed 2.1 Turbo 57, Solar Pro 4 55). The right pick depends on what you value most.

  1. ByteDance Seed

    Seed 2.1 Turbo

    Released Jun 23, 2026

    57/100
    • ECI—
    • Price$0.445 / $2.23
    • Context256K
  2. Upstage

    Solar Pro 4

    Released Aug 6, 2026

    55/100
    • ECI—
    • Price$0.30 / $1.20
    • Context524K
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Too close to call

It is close. Our weighted score puts them within 3 points (Seed 2.1 Turbo 57/100, Solar Pro 4 55/100), so choose by what matters most for your work: Solar Pro 4 on price and Solar Pro 4 for long inputs. 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 priceSolar Pro 4Solar Pro 4 $0.525 · Seed 2.1 Turbo $0.891 per 1M tokens (3:1 blend)
  • Longest contextSolar Pro 4Solar Pro 4 524,288 · Seed 2.1 Turbo 256,000 tokens
  • Widest inputsSeed 2.1 TurboSeed 2.1 Turbo: Text, Images, Video · Solar Pro 4: Text
  • Self-hostingNo open weightsBoth are available only through APIs
How the score is built
MeasureWeightSeed 2.1 TurboSolar Pro 4
Price50%5263
Inputs & features30%8045
Context window20%3649
Overall100%57/10055/100

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.

Seed 2.1 Turbo vs Solar Pro 4 specifications side by side
SpecificationSeed 2.1 TurboByteDance SeedSolar Pro 4Upstage
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.445$0.30 (best)
Output$2.23$1.20 (best)
Cached input$0.089$0.06 (best)
Blended (3:1)$0.891$0.525 (best)
Long-context rateSame rateSame rate
Price sourceOfficial Volcengine Ark APIOfficial Upstage API
Limits
Context window256,000 tokens524,288 tokens (best)
Max output256,000 tokens (best)131,072 tokens
Inputs and features
TextYesYes
ImagesYesNo
PDFsNoNo
AudioNoNo
VideoYesNo
ReasoningYesminimal · low · medium · high · xhigh · maxYesminimal · low · medium · high · xhigh · max
Tool callingYesYes
Structured outputYesYes
Availability
WeightsProprietaryProprietary
API model IDdoubao-seed-2-1-turbo-260628solar-pro4
API providers4 (best)3
ReleasedJun 23, 2026Aug 6, 2026
Knowledge cutoff—Feb 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.

  • Seed 2.1 Turbo$8.91
  • Solar Pro 4$5.40
04 — Questions

Which should you choose?

Which is better: Seed 2.1 Turbo or Solar Pro 4?

It is close. Our weighted score puts them within 3 points (Seed 2.1 Turbo 57/100, Solar Pro 4 55/100), so choose by what matters most for your work: Solar Pro 4 on price and Solar Pro 4 for long inputs. 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, Seed 2.1 Turbo or Solar Pro 4?

Solar Pro 4 is cheaper at $0.30 input / $1.20 output per million tokens (official Upstage 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 $0.525 per million tokens for Solar Pro 4 versus $0.891 for Seed 2.1 Turbo (1.7× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Seed 2.1 Turbo has not been scored yet and Solar Pro 4 has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Seed 2.1 Turbo and Solar Pro 4 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?

Solar Pro 4 has the largest context window at 524,288 tokens, against 256,000 for Seed 2.1 Turbo. Maximum output per response: Seed 2.1 Turbo up to 256,000, Solar Pro 4 up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Seed 2.1 Turbo accepts text, images and video; Solar Pro 4 accepts text. Seed 2.1 Turbo handles the widest range of inputs.

Are any of these open source?

No. Seed 2.1 Turbo and Solar Pro 4 are proprietary and only available through APIs and apps.

Which is newer?

Solar Pro 4 is the newest, released Aug 6, 2026. Seed 2.1 Turbo came out Jun 23, 2026. Knowledge cutoff: Solar Pro 4 Feb 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.