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Comparison · 2 models · Updated Oct 4, 2026

Step 3.5 Flash 2603 vs Trinity Large Thinking

Step 3.5 Flash 2603 comes out ahead, 62 to 55 on our weighted score, and it is the cheaper option too.

  1. Our pick

    StepFun

    Step 3.5 Flash 2603

    Released Apr 2, 2026

    62/100
    • ECI—
    • Price$0.10 / $0.30
    • Context256K
    Full specs Remove Step 3.5 Flash 2603

  2. Arcee AI

    Trinity Large Thinking

    Released Apr 1, 2026Beta

    55/100
    • ECI—
    • Price$0.25 / $0.80
    • Context524K
    Full specs Remove Trinity Large Thinking

  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Step 3.5 Flash 2603 is our pick

Step 3.5 Flash 2603 is the better all-round choice, scoring 62/100 against Trinity Large Thinking (55). It leads on price. Trinity Large Thinking wins on 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 priceStep 3.5 Flash 2603Step 3.5 Flash 2603 $0.15 · Trinity Large Thinking $0.388 per 1M tokens (3:1 blend)
  • Longest contextTrinity Large ThinkingTrinity Large Thinking 524,288 · Step 3.5 Flash 2603 256,000 tokens
  • Widest inputsSame inputsStep 3.5 Flash 2603: Text · Trinity Large Thinking: Text
  • Self-hostingAll open weightsEvery model here can be downloaded and run on your own hardware
How the score is built
MeasureWeightStep 3.5 Flash 2603Trinity Large Thinking
Price50%8969
Inputs & features30%3535
Context window20%3649
Overall100%62/10055/100

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.

Step 3.5 Flash 2603 vs Trinity Large Thinking specifications side by side
SpecificationStep 3.5 Flash 2603StepFunTrinity Large ThinkingArcee AI
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.10 (best)$0.25
Output$0.30 (best)$0.80
Cached input$0.02 (best)$0.06
Blended (3:1)$0.15 (best)$0.388
Long-context rateSame rateSame rate
Price sourceOfficial StepFun (Global) APIOfficial Arcee API
Limits
Context window256,000 tokens524,288 tokens (best)
Max output256,000 tokens262,144 tokens (best)
Inputs and features
TextYesYes
ImagesNoNo
PDFsNoNo
AudioNoNo
VideoNoNo
ReasoningYeslow · highYes
Tool callingYesYes
Structured outputNoNo
Availability
WeightsOpenOpenOpenMDW-1.1
API model IDstep-3.5-flash-2603trinity-large-thinking
API providers36 (best)
ReleasedApr 2, 2026Apr 1, 2026
Knowledge cutoffJan 2025—
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 3.5 Flash 2603$1.60
  • Trinity Large Thinking$4.10
04 — Questions

Which should you choose?

Which is better: Step 3.5 Flash 2603 or Trinity Large Thinking?

Step 3.5 Flash 2603 is the better all-round choice, scoring 62/100 against Trinity Large Thinking (55). It leads on price. Trinity Large Thinking wins on 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, Step 3.5 Flash 2603 or Trinity Large Thinking?

Step 3.5 Flash 2603 is cheaper at $0.10 input / $0.30 output per million tokens (official StepFun (Global) API price). Trinity Large Thinking costs $0.25 input / $0.80 output per million tokens (official Arcee API price). At a typical mix of three input tokens to one output token, that is $0.15 per million tokens for Step 3.5 Flash 2603 versus $0.388 for Trinity Large Thinking (2.6× as much).

Which scores higher on benchmarks?

There is no independent benchmark that covers both models yet. Step 3.5 Flash 2603 has not been scored yet and Trinity Large Thinking has not been scored yet.

Which is better for coding?

There are no published SWE-bench Verified results for Step 3.5 Flash 2603 and Trinity Large Thinking 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?

Trinity Large Thinking has the largest context window at 524,288 tokens, against 256,000 for Step 3.5 Flash 2603. Maximum output per response: Step 3.5 Flash 2603 up to 256,000, Trinity Large Thinking up to 262,144 tokens.

Which can read images, PDFs, audio or video?

Step 3.5 Flash 2603 accepts text; Trinity Large Thinking accepts text. They handle the same number of input types.

Are any of these open source?

Yes, both publish their weights (OpenMDW-1.1), so you can self-host them.

Which is newer?

Step 3.5 Flash 2603 is the newest, released Apr 2, 2026. Trinity Large Thinking came out Apr 1, 2026. Knowledge cutoff: Step 3.5 Flash 2603 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.

05 — Keep comparing

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