ZMIME
Comparison · 2 models · Updated Oct 4, 2026

Step 3.5 Flash 2603 vs Qwen3.8 Flash

Qwen3.8 Flash comes out ahead, 76 to 62 on our weighted score, though Step 3.5 Flash 2603 is 35% cheaper per token.

  1. StepFun

    Step 3.5 Flash 2603

    Released Apr 2, 2026

    62/100
    • ECI—
    • Price$0.10 / $0.30
    • Context256K
  2. Our pick

    Alibaba (Qwen)

    Qwen3.8 Flash

    Released Aug 26, 2026

    76/100
    • ECI—
    • Price$0.15 / $0.47
    • Context1M
  3. Add a model

    Make it a three-way comparison.

01 — Verdict

Qwen3.8 Flash is our pick

Qwen3.8 Flash is the better all-round choice, scoring 76/100 against Step 3.5 Flash 2603 (62). It leads on inputs & features and context window. Step 3.5 Flash 2603 wins on price. 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 · Qwen3.8 Flash $0.23 per 1M tokens (3:1 blend)
  • Longest contextQwen3.8 FlashQwen3.8 Flash 1,000,000 · Step 3.5 Flash 2603 256,000 tokens
  • Widest inputsQwen3.8 FlashStep 3.5 Flash 2603: Text · Qwen3.8 Flash: Text, Images, Video
  • Self-hostingStep 3.5 Flash 2603Publishes downloadable weights
How the score is built
MeasureWeightStep 3.5 Flash 2603Qwen3.8 Flash
Price50%8980
Inputs & features30%3580
Context window20%3660
Overall100%62/10076/100

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 Qwen3.8 Flash specifications side by side
SpecificationStep 3.5 Flash 2603StepFunQwen3.8 FlashAlibaba (Qwen)
Capability
Capabilities Index (ECI)——
ECI rank——
Price per million tokens
Input$0.10 (best)$0.15
Output$0.30 (best)$0.47
Cached input$0.02$0.016 (best)
Blended (3:1)$0.15 (best)$0.23
Long-context rateSame rateSame rate
Price sourceOfficial StepFun (Global) APIOfficial Alibaba API
Limits
Context window256,000 tokens1,000,000 tokens (best)
Max output256,000 tokens (best)131,072 tokens
Inputs and features
TextYesYes
ImagesNoYes
PDFsNoNo
AudioNoNo
VideoNoYes
ReasoningYeslow · highYeslow · medium · xhigh
Tool callingYesYes
Structured outputNoYes
Availability
WeightsOpenProprietary
API model IDstep-3.5-flash-2603qwen3.8-flash
API providers323 (best)
ReleasedApr 2, 2026Aug 26, 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
  • Qwen3.8 Flash$2.44
04 — Questions

Which should you choose?

Which is better: Step 3.5 Flash 2603 or Qwen3.8 Flash?

Qwen3.8 Flash is the better all-round choice, scoring 76/100 against Step 3.5 Flash 2603 (62). It leads on inputs & features and context window. Step 3.5 Flash 2603 wins on price. 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 Qwen3.8 Flash?

Step 3.5 Flash 2603 is cheaper at $0.10 input / $0.30 output per million tokens (official StepFun (Global) API price). Qwen3.8 Flash costs $0.15 input / $0.47 output per million tokens (official Alibaba 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 $0.23 for Qwen3.8 Flash (1.5× 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 Qwen3.8 Flash 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 Qwen3.8 Flash 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?

Qwen3.8 Flash has the largest context window at 1,000,000 tokens, against 256,000 for Step 3.5 Flash 2603. Maximum output per response: Step 3.5 Flash 2603 up to 256,000, Qwen3.8 Flash up to 131,072 tokens.

Which can read images, PDFs, audio or video?

Step 3.5 Flash 2603 accepts text; Qwen3.8 Flash accepts text, images and video. Qwen3.8 Flash handles the widest range of inputs.

Are any of these open source?

Step 3.5 Flash 2603 publishes its weights and can be self-hosted; Qwen3.8 Flash is proprietary.

Which is newer?

Qwen3.8 Flash is the newest, released Aug 26, 2026. Step 3.5 Flash 2603 came out Apr 2, 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.